BARRIER-FREE HDB KITCHEN DESIGN FOR WHEELCHAIR USERS Vol. I XIE HONGYAN (B.E. (Hons.), Xi’an Jiaotong University, China) A THESIS SUBMITTED FOR THE DEGREE OF MASTER OF ARTS (ARCH.) DEPARTMENT OF ARCHITECTURE NATIONAL UNIVERSITY OF SINGAPORE 2003 Dedicated to my beloved family ACKNOWLEDGEMENTS I wish to express my sincere thanks to the National University of Singapore and to the individuals who have in many ways supported and assisted in this dissertation. I would like to thank my previous supervisors, Kenneth J. Parker and James D. Harrison, for their valuable advice, patience, and guidance throughout the research. However, because of my medical absence, both of them left before I finished my research. Great appreciation goes also to Mr. Liem Andre, my supervisor towards the end of my candidature, for his kind regard during my whole research process, his valuable advice and critical comments on this thesis. My appreciation should also extend to Dr. Pinna Indorf, for her critical insights, which helped me to focus and direct my research. My thanks also go to all the people who have participated in the pilot anthropometric studies of the elderly persons and wheelchair users in this thesis. Great thanks to Judy Wee, the president of the Handicaps Welfare Association; Mr. Subrata Banerjee, the Manager of the Rehabilitation Centre, Handicaps Welfare Association; Mr. Li Muyan, the manager of the Singapore Buddhist Lodge; and Ms. Miaoye. Without their help, the anthropometric studies presented here would not have been possible. I am also deeply grateful to the owners of the investigated kitchens, for their hospitality and kindness. I also wish to thank my CASA friends, who helped me during hard times and made my life at NUS enjoyable. Last but not least, thanks to my beloved parents and family, who have always supported and cared for me. Without their love, this endeavor would lack any meaning. i SUMMARY Barrier-free kitchen is imperative for disabled persons, especially when they live independently. For a wheelchair user, he/she may face many barriers to use a kitchen. This research investigates the physical barriers to wheelchair users in small home kitchens in Singapore. The objectives of this research are mainly three: 1) To identify the primary barriers (on the physical aspect) for wheelchair users in small HDB kitchens. 2) To understand the current situations of and reasons for these barriers. 3) To give recommendations for barrier-free kitchen design. First, through the literature review and field investigation of some kitchens used by wheelchair users, the primary physical barriers were identified. It was found that the barriers could be roughly classified into two categories: one was highly related with the wheelchair user’ reach and the height of the appliances; the other was highly related with the turning spaces and kitchen layouts. Second, a pilot study on the wheelchair user’s reach was conducted on 32 wheelchair persons. The purpose of this study was to know the rough reach range of the wheelchair users and then how the kitchen could be designed according to their reach range and body dimensions. The study results were used to design the mock-up kitchens. Third, the layouts of the HDB kitchens from 1978-1999 were analyzed according to the Singapore, NKBA and ADA Guidelines (Building and Construction Authority, 2002; Peterson, 1998; Kearney, 1995). The analyzed aspects involved: (1) minimum width of the different kitchen layouts; (2) minimum width of a wall with doors; (3) area; (4) shape and (5) location of sink, cooker, refrigerator, washing machine and clothes drying. From the schematic analysis, some recommendations were derived for the barrier-free kitchen design. ii Finally, based on the measuring results of the wheelchair user’s reaches and the schematic analysis, three kitchens were designed. True scale kitchen mock-ups were built and 12 wheelchair users were chosen to test the kitchens. During the testing, the kitchens were improved and tested once more. From the tests, one “Optimum small kitchen” (area is 9.6m2) and one “Minimum small kitchen” (area is 7.4 m2) were derived. It was also found that in the existing guidelines recommendations were unavailable on some important issues such as the approaching space to a refrigerator and the different requirements of different types of wheelchair users. These issues should be further investigated in future and recommendations provided. There were also some recommendations derived from the research on the detailed design of the barrier-free kitchen. iii LIST OF ACRONYMS ADA – Americans with Disabilities Act ADLs – Activities of Daily Living ANSI – American National Standard Institute HDB – Housing and Development Board HWA – Handicaps Welfare Association ICF – International Classification of Functioning, Disability and Health NKBA – National Kitchen & Bath Association (USA) PWD – Public Works Department SDD – Scottish Development Department UFAS – Uniform Federal Accessibility Standards UNESCAP – United Nation Economic and Social Commission for Asia and the Pacific URA – Urban Redevelopment Authority iv TABLE OF CONTENTS VOLUME I ACKNOWLEDGEMENTS..............................................................................................I SUMMARY....................................................................................................................II LIST OF ACRONYMS ................................................................................................ IV TABLE OF CONTENTS............................................................................................... V LIST OF FIGURES ...................................................................................................... X LIST OF TABLES ..................................................................................................... XIV CHAPTER I. INTRODUCTION .....................................................................................1 1.1. Background.......................................................................................................1 1.2. Research Objectives ........................................................................................3 1.3. Research Methodology ....................................................................................3 1.4. Research Scope................................................................................................7 1.4.1 Scope of the Wheelchair Users................................................................................ 7 1.4.2 Scope of the Barriers in Kitchen............................................................................. 7 1.4.3 Scope of the Operations and Appliances in HDB Kitchens for Wheelchair Users ................................................................................................................................... 8 CHAPTER II. LITERATURE REVIEW ..........................................................................9 2.1. Concepts of the Disability, Accessible, Persons with Disabilities and Wheelchair Users ....................................................................................................9 2.2. History of Barrier-free Design .........................................................................9 2.3. Barrier-free Design in Singapore ....................................................................9 2.4. Literature Review of the Established Codes, Guidelines, and Related Researches ............................................................................................................10 CHAPTER III. IDENTIFYING THE PRIMARY BARRIERS FOR WHEELCHAIR USERS IN HDB KITCHENS..............................................................................12 3.1. Selection of Kitchens Used by Wheelchair Users .......................................12 3.2. Observations...................................................................................................13 3.2.1. Floor ....................................................................................................................... 13 3.2.2. Countertop............................................................................................................. 14 3.2.3. Wall Cabinet and Corner Cabinet....................................................................... 14 3.2.4. Ventilation Hoods, Sockets and Switches............................................................ 15 3.2.5. Washing Machine and Clothes Drying ............................................................... 15 3.3. Floor Plan of the Five Kitchens .....................................................................15 3.4. Summary .........................................................................................................17 CHAPTER IV. VERTICAL DESIGN OF KITCHENS ..................................................18 4.1. Subjects...........................................................................................................19 4.2. Method for Taking Measurements ................................................................20 4.3. Data Statistics .................................................................................................21 v 4.4. Measurement Results and Discussion .........................................................24 4.4.1. Upward Reach ....................................................................................................... 24 4.4.2. Up-forward Reach to a Wall ................................................................................ 25 4.4.3. Down-forward Reach to a Wall ........................................................................... 25 4.4.4. Downward Reach Laterally ................................................................................. 26 4.4.5. Forward Reach over a Table................................................................................ 26 4.4.6. Lateral Reach over a Table .................................................................................. 29 4.4.7. Knee Height, Wheelchair Armrest Height and Countertop Height ................. 29 4.4.8. Summary of the Reach ......................................................................................... 33 4.5. Accessible Cabinets.......................................................................................33 4.6. Clothes Washing and Drying.........................................................................34 CHAPTER V. FLOOR PLAN DESIGN OF SMALL KITCHENS FOR WHEELCHAIR USERS...............................................................................................................36 5.1. Dimensions for Graphic Analysis .................................................................36 5.1.1. Approaching Spaces at Doors .............................................................................. 37 5.1.1.1. Door width ....................................................................................................... 38 5.1.1.2. Approaching spaces at doors ........................................................................... 38 5.1.1.3. Tests at HWA.................................................................................................... 39 5.1.2. Turning Space for Wheelchair Users .................................................................. 42 5.1.2.1. Tests at HWA.................................................................................................... 44 5.1.3. Minimum Width of the Different Kitchen Layouts ........................................... 46 5.1.4. Minimum Width of a Wall with Doors ............................................................... 49 5.1.5. Clear Floor Space for a Wheelchair User at Appliances ................................... 51 5.2. Setting up the Database of Kitchen and the Criteria for Graphic Analysis .................................................................................................................................52 5.2.1. Setting up the Database of Kitchen ..................................................................... 53 5.2.2. Setting the Criteria for Graphic Analysis ........................................................... 55 5.3. Floor Plan Analyses of the HDB Kitchens....................................................55 5.3.1. Basic Area Requirement....................................................................................... 55 5.3.1.1. Kitchen analyses .............................................................................................. 56 5.3.2. Kitchen Shapes ...................................................................................................... 57 5.3.2.1. Kitchen analyses .............................................................................................. 59 5.3.3. Place of Sink and Cooker ..................................................................................... 60 5.3.3.1. Cooking process and routes ............................................................................. 61 5.3.3.2. Limitation ......................................................................................................... 64 5.3.3.3. Place of Sink and Cooker................................................................................. 65 5.3.4. Place of Refrigerator............................................................................................. 66 5.3.4.1. Refrigerator’s place related to the sink and cooker......................................... 66 5.3.4.2. Refrigerator’s door direction and landing space............................................. 66 5.3.5. Place of Washing Machine and Clothes Drying ................................................. 68 5.3.5.1. Location of washing machine........................................................................... 68 5.3.5.2. Clothes drying .................................................................................................. 68 CHAPTER VI. TESTS ON BARRIER-FREE KITCHEN DESIGNS ............................73 6.1. The Optimum Small Kitchen Designed for Test ..........................................73 6.1.1. Floor Plan Design of the Optimum Small Kitchen............................................. 73 6.1.2. Vertical Design of the Optimum Small Kitchen................................................. 76 6.2. Two Minimum Small Kitchen Designed for Test..........................................78 6.2.1. The First Design .................................................................................................... 79 6.2.2. The Second Design ................................................................................................ 81 6.3. Setting up Kitchen Mock-ups ........................................................................84 vi 6.4. Test Scenarios ................................................................................................87 6.5. Test Procedure ...............................................................................................87 6.6. Subjects...........................................................................................................88 6.7. Test Results of the Optimum Small Kitchen Design (Kitchen O1).............89 6.7.1. Scenario 1............................................................................................................... 89 6.7.1.1. Approaching from door to refrigerator to sink ................................................ 89 6.7.1.2. How to carry items ........................................................................................... 97 6.7.1.3. Working at the sink and cooker........................................................................ 98 6.7.1.4. Space ................................................................................................................ 99 6.7.2. Scenario 2............................................................................................................. 100 6.7.3. Scenario 3............................................................................................................. 106 6.7.3.1. Cabinet near the cooker ................................................................................. 106 6.7.3.2. Rotating cabinet ............................................................................................. 108 6.7.3.3. Cabinet beside the refrigerator ...................................................................... 109 6.7.3.4. Wall cabinet ................................................................................................... 111 6.7.3.5. Storage ........................................................................................................... 111 6.7.4. Scenario 4............................................................................................................. 112 6.7.5. Modifications of Kitchen O1 .............................................................................. 113 6.8. Test Results of the First Modified Design of Kitchen O1 (Kitchen O1m1) ...............................................................................................................................115 6.8.1. Approaching from Door to Refrigerator to Sink ............................................. 116 6.8.2. Approaching the Microwave Oven.................................................................... 117 6.8.3. Using the Microwave Oven ................................................................................ 118 6.8.4. Washing Machine................................................................................................ 119 6.8.5. Storage.................................................................................................................. 120 6.8.6. Sink....................................................................................................................... 120 6.9. Test Results of the Second Modified Design of Kitchen O1 (Kitchen O1m2) ...................................................................................................................120 6.9.1. Approaching from Door to Refrigerator to Sink ............................................. 120 6.9.2. Approaching the Microwave Oven.................................................................... 122 6.9.3. Using the Microwave Oven ................................................................................ 124 6.9.4. Washing Machine................................................................................................ 125 6.9.5. Rotating Cabinet ................................................................................................. 126 6.9.6. Storage.................................................................................................................. 127 6.10. Test Result of the First Minimum Small Kitchen Design (Kitchen M1)..127 6.10.1. Scenario 1........................................................................................................... 127 6.10.1.1. Approaching from door to refrigerator to sink ............................................ 127 6.10.2. Scenario 2........................................................................................................... 131 6.10.3. Scenario 3........................................................................................................... 133 6.10.4. Scenario 4........................................................................................................... 133 6.10.5. Modifications of Kitchen M1............................................................................ 133 6.11. Test Results of the Modified Design of Kitchen M1 (Kitchen M1m1) ....134 6.11.1. Approaching from Door to Refrigerator to Sink ........................................... 135 6.11.2. Approaching and Using the Microwave Oven................................................ 135 6.11.3. Washing Machine.............................................................................................. 136 6.11.4. Storage................................................................................................................ 136 6.12. Test Result of the Second Minimum Small Kitchen Design (Kitchen M2) ...............................................................................................................................137 6.12.1. Scenario 1........................................................................................................... 137 6.12.1.1. Approaching from door to refrigerator to sink ............................................ 137 6.12.2. Scenario 2, Scenario 3 and Scenario 4............................................................. 140 6.12.3. Modifications of Kitchen M2............................................................................ 140 6.13. Test Results of the Modified Design of Kitchen M2 (Kitchen M2m1) ....141 6.13.1. Approaching from Door to Refrigerator to Sink ........................................... 141 6.13.2. Approaching and Using the Microwave Oven................................................ 142 vii 6.13.3. Washing Machine.............................................................................................. 142 6.14. Summary and Findings ..............................................................................143 6.14.1. The “Optimum Small Kitchen” and the “Minimum Small Kitchen” .......... 147 6.14.2. Approaching Methods to a Refrigerator......................................................... 149 6.14.3. Approaching Methods to a Sink or Cooker .................................................... 151 6.14.4. Approaching Methods to a Microwave Oven ................................................. 153 6.14.5. Two Solutions of Making Countertops at the Same Height .......................... 155 6.14.6. Routes from Door to Refrigerator to Sink to Cooker, then from Sink to Microwave Oven ........................................................................................................... 156 6.14.7. Cabinet ............................................................................................................... 157 6.14.8. Washing Machine.............................................................................................. 158 CHAPTER VII. CONCLUSION .................................................................................165 7.1. Important Findings and Recommendations...............................................165 7.1.1. Primary Physical Barriers.................................................................................. 165 7.1.2. Reaches and Countertop Height Determination .............................................. 166 7.1.3. Approaching Spaces at Doors ............................................................................ 169 7.1.4. Tests on Turning Spaces..................................................................................... 170 7.1.5. Minimum Width of the Different Kitchen Layouts and Minimum Width of a Wall with Doors............................................................................................................. 170 7.1.6. Optimum Small Kitchen and Minimum Small Kitchen .................................. 172 7.1.7. Approaching Space to a Refrigerator ............................................................... 174 7.1.8. Location of Refrigerator in Relation to the Living Room Door, Sink and Cooker ............................................................................................................................ 175 7.1.9. Types of Wheelchair Users................................................................................. 176 7.1.10. Other Findings................................................................................................... 176 About refrigerator:...................................................................................................... 176 About countertop: ....................................................................................................... 177 About microwave oven:............................................................................................... 177 About cabinet: ............................................................................................................. 178 About washing machine and clothes drying pole: ...................................................... 180 7.2. Research Contribution .................................................................................180 7.3. Application of the Kitchen Shape ...............................................................181 7.4. Research Limitation .....................................................................................182 7.5. Future Directions ..........................................................................................183 BIBLIOGRAPHY.......................................................................................................185 VOLUME II APPENDIX 1. SCOPE OF OPERATIONS AND THE APPLIANCES IN HDB KITCHENS...........................................................................................................1 APPENDIX 2. CONCEPTS OF THE DISABILITY, ACCESSIBLE, PERSONS WITH DISABILITIES AND WHEELCHAIR USERS ......................................................3 APPENDIX 3. HISTORY OF BARRIER-FREE DESIGN ..............................................4 APPENDIX 4. OBSERVATIONS IN THE FIVE INVESTIGATED KITCHENS .............6 APPENDIX 5. ANTHROPOMETRY PRINCIPLES .....................................................14 APPENDIX 6. METHODS FOR MEASURING THE REACHES.................................17 viii APPENDIX 7. ANTHROPOMETRIC DATA OF THE 32 WHEELCHAIR USERS (TABLES) ..........................................................................................................20 APPENDIX 8. ANTHROPOMETRIC DATA OF THE 16 MALE WHEELCHAIR USERS...............................................................................................................23 APPENDIX 9. ANTHROPOMETRIC DATA OF THE 16 FEMALE WHEELCHAIR USERS...............................................................................................................29 APPENDIX 10. ANTHROPOMETRIC DATA OF THE 32 WHEELCHAIR USERS....35 APPENDIX 11. KNEE HEIGHT ..................................................................................40 APPENDIX 12. ACCESSIBLE CABINETS ................................................................43 APPENDIX 13. APPROACHING SPACES AT DOORS ...........................................45 APPENDIX 14. SPACE FOR WHEELCHAIR TURNING ...........................................48 APPENDIX 15. MINIMUM WIDTH OF THE DIFFERENT KITCHEN LAYOUTS .......51 APPENDIX 16. CLEAR FLOOR SPACE FOR A WHEELCHAIR USER AT APPLIANCES....................................................................................................58 APPENDIX 17. DEVELOPMENT OF HDB FLATS AND KITCHENS ........................61 APPENDIX 18. KITCHEN DATABASE ......................................................................66 APPENDIX 19. AREA CRITERION FOR CHOOSING KITCHEN..............................72 APPENDIX 20. EXAMPLES OF SCHEMATIC ANALYSIS ABOUT THE KITCHEN AREA.................................................................................................................75 APPENDIX 21. EXAMPLES OF SCHEMATIC ANALYSIS ABOUT THE KITCHEN SHAPE...............................................................................................................81 APPENDIX 22. EXAMPLE OF SCHEMATIC ANALYSIS ABOUT THE BAD LOCATION OF A SINK .....................................................................................84 APPENDIX 23. METHOD FOR ROUTE TESTING.....................................................85 APPENDIX 24. REFRIGERATOR’S PLACE RELATED TO THE SINK AND COOKER ...........................................................................................................87 APPENDIX 25. EXAMPLE OF SCHEMATIC ANALYSIS ABOUT THE REFRIGERATOR DOOR AND LANDING SPACE ...........................................89 APPENDIX 26. PLACE OF WASHING MACHINE AND CLOTHES DRYING...........90 APPENDIX 27. KITCHEN LAYOUT ANALYSES.......................................................93 APPENDIX 28. TEST SCENARIOS .........................................................................134 APPENDIX 29. OBSERVATIONS AND QUESTIONS IN TESTING KITCHEN O1M1 .........................................................................................................................136 APPENDIX 30. OBSERVATIONS AND QUESTIONS IN TESTING KITCHEN O1M2 .........................................................................................................................137 APPENDIX 31. OBSERVATIONS AND QUESTIONS IN TESTING KITCHEN M1M1 .........................................................................................................................138 APPENDIX 32. OBSERVATIONS AND QUESTIONS IN TESTING KITCHEN M2M1 .........................................................................................................................139 APPENDIX 33. TEST RESULTS OF THE MOCK-UP KITCHENS ..........................140 ix LIST OF FIGURES Figure 1. 1: Research framework. ............................................................................................... 6 Figure 3. 1: Floor layout plan of Kitchen No. 1........................................................................ 16 Figure 3. 2: Floor layout plans of Kitchens No. 2..................................................................... 16 Figure 3. 3: Floor layout plans of Kitchens No. 3..................................................................... 16 Figure 3. 4: Floor layout plan of Kitchen No. 4........................................................................ 17 Figure 3. 5: Floor layout plan of Kitchen No. 5........................................................................ 17 Figure 4. 1: Freezer in the wheelchair user’s reach................................................................... 24 Figure 4. 2: Estimation of the wall cabinet height. ................................................................... 28 Figure 4. 3: The countertop height is decided by the appliance thickness, knee height and armrest height.................................................................................................................... 30 Figure 4. 4: Different types of the wheelchair .......................................................................... 31 Figure 4. 5: Small ancillary countertops below the main countertops. ..................................... 33 Figure 4. 6: Top-loaded washing machine and front-loaded washing machine........................ 34 Figure 4. 7: Device for easy clothes drying. ............................................................................. 35 Figure 5. 1: Different approaching methods at doors................................................................ 39 Figure 5. 2: The first approaching method to a door................................................................. 40 Figure 5. 3: The third approaching method to a door ............................................................... 41 Figure 5. 4: The second approaching method to a door ............................................................ 41 Figure 5. 5: Wheelchair’s fore-wheel was beyond the line....................................................... 42 Figure 5. 6: More space is needed on the latch side of the door. .............................................. 42 Figure 5. 7: Turning radius based on different pivot points...................................................... 43 Figure 5. 8: Turning in a small circle turning space.................................................................. 44 Figure 5. 9: Turning in a large circle turning space. ................................................................. 44 Figure 5. 10: Turning in a T-shaped space................................................................................ 44 Figure 5. 11: Minimum width of the kitchen. ........................................................................... 50 Figure 5. 12: A clear floor space at appliances ......................................................................... 52 Figure 5. 13: Kitchen layout to suit a wheelchair user.............................................................. 56 Figure 5. 14: Traffic area ......................................................................................................... 59 Figure 5. 15: Two routes for instant noodle making in Kitchen 8182-11................................. 62 Figure 5. 16: Lengths of the two routes in each kitchen layout. ............................................... 63 Figure 5. 17: A cooker should not be placed too near a window or a door............................... 65 Figure 5. 18: Refrigerator placement considerations. ............................................................... 67 Figure 6. 1: Plan of the “Optimum small kitchen”.................................................................... 74 Figure 6. 2: A-A section of the “Optimum small kitchen” ....................................................... 77 Figure 6. 3: B-B section of the “Optimum small kitchen”........................................................ 77 Figure 6. 4: The first design of the “Minimum small kitchen”. ................................................ 79 Figure 6. 5: The second design of the “Minimum small kitchen”. ........................................... 82 Figure 6. 6: The mock-up of the “Optimum small kitchen”. .................................................... 84 Figure 6. 7: The mock-up of the first “Minimum small kitchen” ............................................. 84 Figure 6. 8: The mock-up of the second “Minimum small kitchen”......................................... 85 Figure 6. 9: The door of the microwave oven could only be opened at 90o.............................. 85 Figure 6. 10: The inner shelves were made in the refrigerator and rotating cabinets. .............. 86 Figure 6. 11: The pull-out countertop was made. ..................................................................... 86 x Figure 6. 12: The height of inner barrel of the washing machine was simulated. .................... 86 Figure 6. 13: The wooden props and counter legs could be adjusted. ...................................... 86 Figure 6. 14: The three kitchen designs were modified into four kitchens. .............................. 88 Figure 6. 15: The route of a subject from door to refrigerator to sink ...................................... 89 Figure 6. 16: Process of a subject approaching from door to refrigerator to sink..................... 90 Figure 6. 17: The left half and right half of the refrigerator...................................................... 91 Figure 6. 18: The route from door to refrigerator to sink.......................................................... 91 Figure 6. 19: The process of a subject approaching from door to refrigerator to sink.............. 92 Figure 6. 20: The route of a subject approaching from door to refrigerator to sink.................. 93 Figure 6. 21: Process of a subject approaching from door to refrigerator to sink..................... 94 Figure 6. 22: The route of a subject approaching from door to refrigerator to sink.................. 95 Figure 6. 23: Process of a subject approaching from door to refrigerator to sink..................... 96 Figure 6. 24: The wheelchair users easily collided with the cabinets when approaching the refrigerator backward. ....................................................................................................... 97 Figure 6. 25: A wheelchair user dragged the bowl along the countertop.................................. 97 Figure 6. 26: Sink and cooker with knee space could be comfortably used by the wheelchair users. ................................................................................................................................. 98 Figure 6. 27: Cutting the object on the main countertop........................................................... 99 Figure 6. 28: The ventilation hood could be reached by all subjects. ....................................... 99 Figure 6. 29: Frontward approach from the sink to the microwave oven ............................... 100 Figure 6. 30: Backward approach was easier for the wheelchair users who preferred to use the right hand. ....................................................................................................................... 101 Figure 6. 31: For the wheelchair user who preferred to use the right hand, the microwave oven on his/her left was very difficult to use........................................................................... 101 Figure 6. 32: The microwave oven used by a wheelchair user who preferred to use his left arm. ......................................................................................................................................... 101 Figure 6. 33: A subject who approached the microwave oven backward chose the countertop left to the microwave oven.............................................................................................. 102 Figure 6. 34: Either bending forward or turning the body was uncomfortable for the subjects. ......................................................................................................................................... 103 Figure 6. 35: The subjects had to move the food round the door............................................ 103 Figure 6. 36: The bowl could be put on the countertop when a subject was opening or closing the microwave oven’s door. ............................................................................................ 103 Figure 6. 37: The wider pull-out countertop will make shifting a bowl easier. ...................... 104 Figure 6. 38: Shifting a bowl from microwave oven to the countertops beside...................... 104 Figure 6. 39: A step between the main countertop and the pull-out countertop. .................... 105 Figure 6. 40: The microwave oven at the edge of the main countertop. ................................. 105 Figure 6. 41: Approaching the cabinet, utilizing the knee space. ........................................... 106 Figure 6. 42: Approaching the cabinet at an angle.................................................................. 107 Figure 6. 43: Approaching the cabinet laterally...................................................................... 107 Figure 6. 44: Three approaching methods to the cabinet near the cooker............................... 107 Figure 6. 45: The handles installed at the right side of the drawers could be more easily accessed........................................................................................................................... 108 Figure 6. 46: Approaching the rotating cabinet where it was on the user’s left...................... 108 Figure 6. 47: Approaching the rotating cabinet where it was on the user’s right. .................. 109 Figure 6. 48: Two approaching methods to the rotating cabinet............................................. 109 Figure 6. 49: Two approaching methods to the cabinet right to the refrigerator (photos) ...... 110 Figure 6. 50: Two approaching methods to the cabinet right to the refrigerator ................... 110 Figure 6. 51: The handles installed at the left side of the drawers could be more easily accessed. ......................................................................................................................................... 111 Figure 6. 52: A subject using a wall cabinet. .......................................................................... 111 Figure 6. 53: Approaching methods to the washing machines. .............................................. 112 Figure 6. 54: Approaching methods to the washing machine and the preferred locations of the clothes hanging pole........................................................................................................ 112 Figure 6. 55: The subjects’ preference of the clothes pole...................................................... 113 xi Figure 6. 56: Layout of the first modified design of Kitchen O1 (Kitchen O1m1) ................ 114 Figure 6. 57: The second improved design of Kitchen O1 (Kitchen O1m2) .......................... 115 Figure 6. 58: The knee space made it easier for the subject to open the refrigerator door and get the object. ........................................................................................................................ 116 Figure 6. 59: The route from door to refrigerator to sink when the knee space was utilized.. 116 Figure 6. 60: The bowl could be put on the countertop left to the refrigerator....................... 117 Figure 6. 61: The approaching route from the sink to the microwave oven ........................... 118 Figure 6. 62: A subject using the microwave oven. ................................................................ 119 Figure 6. 63: The raised washing machine was easy to use.................................................... 119 Figure 6. 64: Approaching route from door to refrigerator to sink ......................................... 121 Figure 6. 65: Process of a subject approaching from door to refrigerator to sink................... 122 Figure 6. 66: Different approaching methods from sink to microwave oven. ........................ 123 Figure 6. 67: Process of a subject using the microwave oven................................................. 124 Figure 6. 68: Approaching methods to the washing machine and the preferred locations of the clothes hanging pole........................................................................................................ 125 Figure 6. 69: Two approaching methods to the rotating cabinet............................................. 126 Figure 6. 70: A subject using the rotating cabinet with the left hand. .................................... 126 Figure 6. 71: A subject using the rotating cabinet with the right hand. .................................. 126 Figure 6. 72: Route of the subjects who preferred to use the right hand................................. 127 Figure 6. 73: Route of the subjects who preferred to use the right hand................................. 128 Figure 6. 74: Process of a subject approaching from door to refrigerator to sink................... 129 Figure 6. 75: Route of the second approaching method used by the subjects who preferred to use the left hand .............................................................................................................. 130 Figure 6. 76: Process of a subject approaching from door to refrigerator to sink................... 130 Figure 6. 77: The process of a subject who used the microwave oven ................................... 132 Figure 6. 78: When a subject sat laterally and the microwave oven was on his right, it was difficult for him to put the bowl to the countertop left to the microwave oven. ............. 132 Figure 6. 79: Layout of the modified design of Kitchen M1 (Kitchen M1m1) ...................... 134 Figure 6. 80: Route of the subjects approaching from door to refrigerator to sink when the knee space was utilized............................................................................................................ 135 Figure 6. 81: The washing machine could be used by different approaching methods. ......... 136 Figure 6. 82: Different approaching methods to the washing machine and the preferred locations of the adjustable clothes pole........................................................................... 136 Figure 6. 83: The route from door to refrigerator to sink........................................................ 137 Figure 6. 84: Process of a subject approaching from door to refrigerator to sink................... 138 Figure 6. 85: Route of the subjects from door to refrigerator to sink...................................... 139 Figure 6. 86: Process of a subject approaching from door to refrigerator to sink................... 139 Figure 6. 87: Layout of the modified design of Kitchen M2 (Kitchen M2m1) ...................... 140 Figure 6. 88: Route of the subjects approaching from door to refrigerator to sink when the knee space was utilized............................................................................................................ 141 Figure 6. 89: Route of the subjects approaching from the door to refrigerator to sink ........... 142 Figure 6. 90: Different approaching methods to the washing machine and the preferred locations of the adjustable clothes pole........................................................................... 143 Figure 6. 91: Layout of Kitchen O1m3................................................................................... 148 Figure 6. 92: Layout of Kitchen M1m2 .................................................................................. 149 Figure 6. 93: Some space should be provided at both sides of the refrigerator. ..................... 151 Figure 6. 94: The first solution of making countertops at the same height............................. 155 Figure 6. 95: The second solution of making countertops at the same height. ....................... 156 Figure 7. 1: (Left) adjustable wall cabinet; ............................................................................. 168 Figure 7. 2: Different approaching methods at doors.............................................................. 169 Figure 7. 3: More space is needed on the latch side of the door. ............................................ 169 Figure 7. 4: Minimum width of a wall with doors. ................................................................. 172 Figure 7. 5: An Optimum small kitchen design (Kitchen O1m3)........................................... 173 Figure 7. 6: A Minimum small kitchen design (Kitchen M1m2)............................................ 173 xii Figure 7. 7: Space for approaching a refrigerator. .................................................................. 175 Figure 7. 8: locations of the door, refrigerator, sink and cooker............................................. 175 Figure 7. 9: Two solutions of making countertops at the same height.................................... 178 Figure 7. 10: Handles on the side from which a wheelchair user is approaching. .................. 179 Figure 7. 11: (Left) knee space for wheelchair users who are good with the left hand or both hands. (Right) knee space for wheelchair users who are good with the right hand or both hands. .............................................................................................................................. 179 Figure 7. 12: Situations in irregular shaped kitchens can be very complex........................... 181 Figure 7. 13: The “Optimum small kitchen” example can be adapted to several irregular shaped kitchens. .............................................................................................................. 182 xiii LIST OF TABLES Table 3. 1: Five investigated kitchens for wheelchair users. .................................................... 12 Table 3. 2: Floor level changes in the five kitchens.................................................................. 13 Table 3. 3: Changes in floor level. ............................................................................................ 13 Table 3. 4: Heights of the countertops in the five kitchens....................................................... 14 Table 3. 5: Heights of the bottoms of the wall cabinets............................................................ 14 Table 3. 6: Heights of the ventilation hoods. ............................................................................ 15 Table 4. 1: Age distribution of the subjects. ............................................................................. 19 Table 4. 2: Ethnic distribution of the subjects........................................................................... 19 Table 4. 3: The health conditions of the subjects...................................................................... 19 Table 4. 4: Comparison between the observations, illustrations, measurement results and their applications. ...................................................................................................................... 23 Table 4. 5: Values of the down-forward reach to a wall and downward reach laterally........... 26 Table 4. 6: Values of the forward reach over a table and lateral reach over a table. ................ 29 Table 4. 7: Measurement results of the knee height.................................................................. 30 Table 4. 8: Measurement result of the wheelchair armrest height. ........................................... 30 Table 4. 9: Recommendations for the kitchen design for wheelchair users.............................. 33 Table 5. 1: Time spent in different methods ............................................................................. 40 Table 5. 2: Recommendations on the turning space. ................................................................ 43 Table 5. 3: Time spent in three different turning spaces........................................................... 45 Table 5. 4: The minimum width for different kitchen layouts. ................................................. 48 Table 5. 5: Recommendations about the clear floor space........................................................ 51 Table 5. 6: Microsoft Access can list data according to different enquiries ............................. 54 Table 5. 7: Shapes of HDB kitchens from 1978 to 1999. ......................................................... 58 Table 5. 8: Lengths of the two routes in each kitchen layout.................................................... 63 Table 5. 9: Summary of the observations, recommendations and applications. ....................... 72 Table 6. 1: The wheelchair users selected for the test............................................................... 88 Table 6. 2: Scenario test results in the seven kitchens. ........................................................... 146 Table 6. 3: Different approaching methods for different wheelchair users............................. 150 Table 6. 4: Different approaching methods for different wheelchair users............................. 152 Table 6. 5: Different approaching methods for different wheelchair users............................. 154 Table 6. 6: Routes of the different types of wheelchair users in different kitchen layouts. .... 164 Table 7. 1: Reaches of the wheelchair users ........................................................................... 166 Table 7. 2: Recommendations for the kitchen design used by wheelchair users. ................... 167 Table 7. 3: The recommended minimum width for different kitchen layouts. ....................... 171 xiv CHAPTER I. INTRODUCTION 1.1. Background As Singapore grows in maturity, attitudes toward disability have been gradually changed. Singaporeans adopted the fundamental philosophy that the disabled should be treated as equal members of society. There is no comprehensive survey of the number of disabled people in Singapore, though the number is expected to be many. According to UN Economic and Social Commission for Asia and the Pacific (UNESCAP) (1995), The Central Registry of Disabled People (CRDP) of the Ministry of Community Development in Singapore recorded only persons with permanent disabilities. The total number of registered disabled people in 1988 was 12,526, less than 0.5 per cent of the total population. This percentage was much smaller compared to those of Japan, United States, or Canada. According to Harrison (1988), this was probably because of the different classification criteria employed and absence of strong incentives for registration. Therefore, the figures may not represent the actual number of persons with disabilities, which may be more than the official figures. It may be assumed that a more realistic figure would be 67,000 in 1988 (UNESCAP, 1995). Because the population of disabled people in Singapore is unignorable, it is important to design an environment catering for their needs. Kitchen is important element of the home environment where many tasks include washing, cooking, and sometimes eating are performed. A disabled person may face many barriers in such space if the kitchen is unable to meet their special requirements. A barrier-free kitchen benefits a disabled person whether he/she lives with his/her family or independently. When a disabled person lives with his/her family, of course, his/her family can cook for him/her. But a barrier-free kitchen can provide him/her the opportunity to share the 1 cooking pleasure; thus, this affords him/her self-confidence, dignity and a sense of achievement. Undoubtedly, when a disabled person lives independently, a barrier-free kitchen is necessary. High-rise, high-density housing is the first and majority choice for the population in Singapore where land is precious (Lam, 1988). The Housing and Development Board (HDB) is the sole national authority responsible for physical planning and implementation of public housing. Over 86% of the total population lives in housing produced by the HDB. About 78 percent of these dwellings are owner-occupied (HDB, 1998). As one of the large groups in disabled people, wheelchair users usually face some barriers. According to Goldsmith (1976), the wheelchair user is handicapped in three aspects. “Firstly, whatever condition put him in the wheelchair; the disabilities concerned will be handicapping in themselves. Secondly, he must operate at an eye-level which is some 400 mm lower than that of standing people, which is disadvantageous both physically and psychologically. Thirdly, he rolls around in a cumbersome, awkward, space consuming, distinctive and inelegant vehicle. Whilst the first handicap is outside the designer’s control, the second and third relate to the traditional ergonomic considerations of reach, working level, clearance and access-as such they are potentially soluble.” Kitchens in HDB flats are designed according to certain principles. For example, they are designed not too big, usually attached to a bathroom (Wong and Yeh, 1985). The arrangement of other rooms also influences a kitchen’s floor shape. Some HDB kitchens were built in irregular shapes (HDB, 1977-1999). For these reasons, a wheelchair user who lives in an HDB flat may face some barriers in the kitchen. 2 This research focused on the understanding of the primary barriers for wheelchair users in small HDB kitchens, how the barriers arise and how they can be solved/avoided. The findings will add depth to our understanding of the interactions between wheelchair users and the kitchen. Such an understanding can then help in the creation of supportive home spaces for wheelchair users in future. 1.2. Research Objectives The objectives of this research are mainly three: 1) To identify the primary barriers (on the physical aspect) for wheelchair users in small HDB kitchens. 2) To understand the current situations of and reasons for these barriers. 3) To give recommendations for barrier-free kitchen design. 1.3. Research Methodology There were roughly three steps to the research methodology used. The first step was a literature review and field investigation. The main aim of this step was to identify the primary barriers for the wheelchair users in HDB kitchens. Related knowledge, principles and guidelines were found through reference, such as books, journals, newspaper articles, reports and papers presented in conferences. Field investigations provided more specific information about the present, local conditions of the kitchens used by wheelchair users in Singapore HDB flats. They were necessary for identifying the primary barriers for wheelchair users in the local context. After the barriers had been identified, the barriers were classified into two groups: one group was related to vertical design and user’s reach (such as the height of countertop, cabinet, handle, etc.), and the other group was related to the floor plan design (such as space for turning a wheelchair, kitchen working center layouts, working routes, etc.). A survey on the scope of the operations and appliances in HDB kitchens for wheelchair users was also conducted. The following analyses about the floor plan design were also confined by this survey results. 3 The second step of the research was analyses of the physical layouts according to the two categories. For the vertical design, this study mainly focused on two questions: 1) What is the reachable range of the wheelchair users? 2) What are the proper heights of the countertop and appliances for the wheelchair users? Therefore, a pilot study on anthropometry of wheelchair users was conducted. The purpose of this anthropometric study was to find out the approximate reach range of the wheelchair users and how the kitchen should be designed according to their reach range and body dimensions. There were 16 male and 16 female wheelchair users whose body dimensions and reach range were obtained at the Handicaps Welfare Association (HWA). Based on the measurement results, the suitable heights of the countertop, wall cabinets, appliances, handles, switches and so on were estimated. The results were applied to the vertical design of the mock-up test kitchens. With regard to floor plan design, the main discussions were about the rational area and layouts of the HDB kitchens from the viewpoint of the barrier-free design for wheelchair users. There were three possible methods of carrying out the kitchen floor plan analysis. The first was to utilize floor plan drawings for floor plan analysis. The second was to construct an experimental kitchen where layouts could be adjusted and rearranged. Wheelchair users would be invited to test the kitchen and in the process, found out barriers in various conditions. The third was to select existing HDB kitchens for floor plan analysis. The third method was impracticable due to the following constraints: (1) it was difficult to select suitable kitchens for sampling because there were many different kitchen types around the whole island; (2) the owner had to agree to allow tests carried out in his/her kitchen; (3) wheelchair users had to be taken to the kitchen for tests. The first method was first chosen for general analyses of the existing kitchen plans. It has the advantage of analyzing kitchen types in Singapore comprehensively. The layouts of the 28 HDB kitchens from 1978-1999 were analyzed by applying three guidelines which are: 4 • The Code on Barrier-Free Accessibility in Buildings, 2002 (Building and Construction Authority, 2002) (abbreviated as Singapore Guidelines in this thesis). • The National Kitchen & Bath Association Presents, Universal Kitchen & Bathroom Planning: Design That Adapts to People (Peterson, 1998) (abbreviated as NKBA Guidelines in this thesis). • The ADA (Americans with Disabilities Act 1990) in Practice (Kearney, 1995) (abbreviated as ADA Guidelines in this thesis). The analyzed aspects involved: (1) area requirement; (2) kitchen shape; (3) place of sink and cooker; (4) place of refrigerator; (5) place of washing machine and clothes drying. From the schematic analyses, some recommendations were derived for the barrier-free kitchen design. The analyses showed that the area for the “optimum small kitchen” should be around 9m2; rectangular shape, which is not too narrow, is well suitable to arrange kitchen appliances. The analyses also showed that there were some requirements on the location of the sink, cooker, refrigerator, washing machine and clothes drying. All these findings were applied to the floor plan design of the mock-up test kitchens. The third step of the research methodology was to test the barrier-free kitchens newly designed. After the general analyses of the existing kitchen plans, three barrier-free kitchens were designed. Then the second method was used to test the kitchen examples. Mock-ups were built in true scale at HWA. 12 wheelchair users took part in the experiment. There were 4 scenarios tested in each kitchen. After the three mock-up test kitchens had been tested, they were modified based on the users’ comments. Then the modified kitchens were tested again. During the testing, supporting surveys were also conducted. Finally, findings were summarized and the recommendations were given. The research framework is illustrated in Figure 1.1. 5 Step 1: Survey and investiga tion Literature review Identify the primary barriers for wheelchair users in HDB kitchens. The barriers were classified into two categories: vertical design and floor plan design. Vertical design Step 2: Vertical design Survey about the operations and appliances in HDB kitchens for wheelchair users Field investigation of five kitchens Reaches Literature review Recommendations in Singapore Guidelines Anthropometric measurements on 32 wheelchair users Floor plan design Singapore, NKBA and ADA Guidelines and other literature Countertop height Turing space for wheelchair users Important dimensions: 1. Upward reach 2. Forward reach over a table 3. Up-forward reach to a wall 4. Down-forward reach to a wall 5. Downward reach laterally 6. Lateral reach over a table 7. Knee height 8. Wheelchair rest height Approaching space to doors Floor space at appliance Tests in HWA 1. Minimum width of the different kitchen layouts 2. Minimum width of a wall with doors 28 HDB kitchens (1978-1999) 1. Area requirement. 2. Kitchen shape. 3. Place of sink and cooker. 4. Place of refrigerator. 5. Place for washing machine and clothes drying. Recommendations on the floor plan design Recommendations on the vertical design Step 2: Floor plan design Three kitchen examples: Kitchen O1, M1, M2 Step 3: Test Kitchen mock-ups tested by 12 wheelchair users Scenario 1 Scenario 2 Kitchen O1m1, O1m2, M1m1, M2m1 Scenario3 Scenario4 Supporting questions Modify and retest Conclusions and recommendations Figure 1. 1: Research framework. 6 1.4. Research Scope 1.4.1 Scope of the Wheelchair Users People use wheelchairs for many different reasons. Some do so because of a sudden change or an accident that takes away their ability to walk. For others, it is because of inner diseases. No matter how a person became a wheelchair user, in this thesis, only those who were able to move wheelchairs by themselves were involved as research subjects. Some wheelchair users had serious diseases that did not allow them to propel the wheelchairs by themselves. They were not involved in this thesis. 1.4.2 Scope of the Barriers in Kitchen There are different types of barriers. They can be generated from physical, social and attitudinal world to impact on the wheelchair user’s performance. According to Goldsmith (1997), “by the social version of disability, … disabled people are those who are disabled on account of social barriers, by societal institutions which exclude them, and by the apparatus of architectural and other impediments which place them at a disadvantage.” The social version of disability can cause disabilities in employment, education, transport and so on. However, this thesis mainly investigated the barriers in the physical aspect rather than the social aspect. Among the physical barriers, some barriers were highly related to the user’s cognition. For example, inadequate illumination or ambiguous indications on appliances could cause barriers to the user. These cognitive barriers were not considered in this thesis. The space scope of the barriers was the kitchen. The boundary consisted of the kitchen walls and doors. Other rooms linking to the kitchen were not discussed. 7 1.4.3 Scope of the Operations and Appliances in HDB Kitchens for Wheelchair Users Many operations can be conducted in a kitchen. There are also varied appliances used in a kitchen. In order to identify the important operations and appliances accommodated in HDB kitchens for wheelchair users, a survey was conducted at HWA (for details please see Appendix 1: Scope of Operations and the Appliances in HDB Kitchens). It was found that cooking and laundry are the most important operations in HDB kitchens. Wheelchair users prefer to do light cooking. The sink, cooker, refrigerator and washing machine are the most often used appliances in HDB kitchens. A microwave oven is often used in the kitchen. Therefore, in this thesis the operations conducted in a kitchen were strictly limited to cooking and laundry. The basic appliances were limited to a sink, cooker, refrigerator, microwave oven and washing machine. 8 CHAPTER II. LITERATURE REVIEW 2.1. Concepts of the Disability, Accessible, Persons with Disabilities and Wheelchair Users The concept of the “Disability” was quoted from the International Classification of Functioning, Disability and Health (ICF) (WHO, 2004); The concepts of “accessible”, “persons with disabilities” and “wheelchair users” used in this thesis were offered by the Building and Construction Authority (2002). For details please see Appendix 2: Concepts of the Disability, Accessible, Persons with Disabilities and Wheelchair Users. 2.2. History of Barrier-free Design The barrier-free movement began in 1950s in response to demands by disabled veterans and advocates for people with disabilities to have opportunities in education and employment. From the 1950s to the 1960s, along with the growing awareness of the need of accessibility, a number of states in USA set up their own accessibility standards (Story et al., 1998). In 1990 the Americans with Disabilities Act (ADA) was passed, and guidelines were passed in 1991 (Kearney, 1995). Equal rights are ensured in employment, access to places of public accommodation, services, programs, public transportation and telecommunications. For details please see Appendix 3: History of Barrier-free Design. 2.3. Barrier-free Design in Singapore According to UNESCAP (1995), most of the recent developments in Singapore have been strongly influenced by market forces. In recent years, a set of "Agendas for Action" had been proposed. The purpose of the agendas was to look at aspects of Singaporean society which would benefit from a more "humane" form of social development. Studies were conducted to assess the needs of minority groups. 9 In April 1988, the Advisory Council on the Disabled was established under the purview of the Ministry of Community Development. The mission of the organization is to create an environment with supportive facilities so that disabled people can develop their physical, mental, and social capabilities to the fullest extent (Council on Tall Buildings and Urban Habitat, 1992). In 1989, the Code on Barrier-free Accessibility in Buildings (Public Works Department, 1990) was issued. It was revised in 1995 (Public Works Department, 1995). The latest version was issued in 2002 (Building and Construction Authority, 2002). Under the Effort of the Urban Redevelopment Authority (URA) and the Public Works Department (PWD), some public spaces such as Streets, Buildings, Bus and MRT stations became more accessible. However, there seem to have been no published guidelines on designing kitchens for disabled people in Singapore. Moreover, studies on this aspect are quite few. No local studies on the barrier-free kitchen were found during the search for relevant literature. 2.4. Literature Review of the Established Codes, Guidelines, and Related Researches A literature review was conducted on the barriers for wheelchair users in a kitchen (Donlan et al., 1978; Goldsmith, 1997; Grandjean, 1973; Conran, 1977; Peterson, 1998; Scottish Development Department, 1979). The literature shows that for wheelchair users, the barriers are quite similar. The physical barriers are mainly in: steps at the door, too high countertops, lack of knee space, inaccessible cabinets and inaccessible switches/outlets. 10 Some codes and guidelines were reviewed (American National Standard Institute, 1992; National Standard of Canada, 1995; British Standards Institution, 2000; Peterson, 1998; Kearney, 1995). Because the barrier-free kitchen design is closely related with the wheelchair users’ body dimensions and reaches, anthropometry and ergonomics theory and researches on the wheelchair users were reviewed (Batiste and Loy, 2002; Damon et al., 1971; Grandjean, 1973; Grandjean, 1988; Ham et al., 1998; Jarosz, 1996; Floyd et al., 1966). However, most of them are Western codes, guidelines and studies; thus, they cannot be directly applied to the local context. The only local code is The Code on Barrier-free Accessibility in Building, 2002 (Building and Construction Authority, 2002). But in this code, only a little information is available about the kitchen design for wheelchair users. 11 CHAPTER III. IDENTIFYING THE PRIMARY BARRIERS FOR WHEELCHAIR USERS IN HDB KITCHENS 3.1. Selection of Kitchens Used by Wheelchair Users Field investigations were conducted in order to acquire more information about the local HDB kitchens for wheelchair users. Five wheelchair users, who live in HDB flats, were selected among clients of HWA in Singapore. They were selected according to the rules that the participants more to be both male and female, old and young, fat and thin, and strong and weak. Investigations were conducted in the five kitchens; the subjects performed certain tasks in the kitchen following the investigator’s requests and the primary barriers encountered by the wheelchair users were recorded. The investigated kitchens are listed in the Table 3.1. No. 1 2 3 Owner’s Age and gender 58, male 38, female 42, female Owner’s health status Flat type Kitchen area Stroke, Fat Paraplegia, fat Paralysis, thin 4-room flat 4-room flat 4-room flat 4 32, female Paraplegia, weak and thin 3-room flat 5 43, male Paraplegia, strong 3-room flat 10.8 m2 10.22m2 13.5m2 7.53 m2 (before modification) 14.9m2 (after modification) 15.69m2 Whether modified Unmodified Unmodified Unmodified Modified Modified Table 3. 1: Five investigated kitchens for wheelchair users. Among the five kitchens, three of them (No.1, 2, 3) were ‘common’ ones which had not been modified. Kitchen No. 4 was newly built. Its owner had to move into a new flat which is on a floor that the elevator can access after she had got handicapped; therefore, she had a chance to build the kitchen according to her needs. The last kitchen (No.5) was modified after its owner had got handicapped; he stayed in his own flat because the elevator can access to the floor. The following is the summary of the observations in the five kitchens. For the details please see Appendix 4: Observations in the Five Investigated Kitchens. In order to make a comparison among the observations, recommendations in the literature and the measurement results of the reaches, the findings of the observations were also tabulated in Table 4.4 (p 22- 12 23). The table shows the important dimensions which were observed, measured and the comparisons between the recommendations in literature and measurement results. 3.2. Observations 3.2.1. Floor The situations of the floor level in the five kitchens are shown in Table 3.2. Kitchen Floor level Any modification Owner’s comment No. 1 Two thresholds (12cm high) between the kitchen and bathroom. A simple ramp was made. Very inconvenient No. 2 No any curbs/ thresholds No. 3 No. 4 No. 5 Easy to access the door No any curbs/ thresholds Kitchen floor is lower than that of other rooms The kitchen floor is 6cm lower than that of the living room Easy to access the door The floor had been raised up Very easy to access the kitchen A ramp was built Good Table 3. 2: Floor level changes in the five kitchens. Change of the floor level may cause inconvenience or inaccessibility for wheelchair users. Therefore, steps and thresholds inside a flat should be avoided as much as possible. If a step or threshold must be set in a flat, the height of the steps and thresholds should be low so that a wheelchair can easily get across them. According to the NKBA Guidelines (Peterson, 1998, p12), “The threshold should not be higher than ½” (1.27cm) (beveled) or ¼” (0.64cm) (Square).” According to the Singapore Guidelines (Building and Construction Authority, 2002), “Kerbs for roll-in shower stall shall not be more than 10 mm high, beveled at a slope of 1:2.” The Singapore Guidelines also recommends that any changes in level shall conform to Table 3.3. A step or threshold should be designed following these guidelines. Changes in Vertical Rise, (mm) 0 to 15 15.1 to 50 50.1 to 200 Exceeding 200 Gradient not Steeper than 1:2 1:5 1:10 1:12 Table 3. 3: Changes in floor level (Source: Building and Construction Authority, 2002). 13 3.2.2. Countertop The countertop height of each kitchen was measured and the owner’s comment was also recorded. The results are listed in Table 3.4. Kitchen Countertop height Knee space Owner’s comment No. 1 84cm Not available A little high No. 2 88cm Not available Too high No. 3 89cm Not available Too high No. 4 75cm Not available Suitable No. 5 85cm Not available Suitable Table 3. 4: Heights of the countertops in the five kitchens. There were mainly two problems about the countertop: one was the unsuitable height, the other was the lack of knee space. Working at a countertop which was too high, a wheelchair user had several difficulties: (1) he/she could not see inside the pot on the cooker; (2) he/she could not reach the bottom of the sink; (3) he/she had to raise his/her arm very high when stirring ingredients in the pot, washing ingredients in the sink or cutting ingredients on the countertop; (4) without the knee space, a wheelchair user had to sit at the countertop laterally; he/she had to turn his/her body facing the sink or cooker and so it was very uncomfortable. 3.2.3. Wall Cabinet and Corner Cabinet Table 3.5 shows the heights of the bottoms of the wall cabinets in the five kitchens. Except for Kitchen No. 1, all the wall cabinets were unreachable by the owners. Kitchen No. 1 No. 2 No. 3 No. 4 No. 5 Height of the wall cabinet’s bottom No wall cabinet 155cm 134cm 135cm 150cm Owner’s comment / Unreachable Unreachable Unreachable Unreachable Table 3. 5: Heights of the bottoms of the wall cabinets. For the lowest drawers of the base cabinet and the corner cabinet, all the wheelchair users had great difficulty in reaching the objects. 14 3.2.4. Ventilation Hoods, Sockets and Switches In the two modified kitchens, the ventilation hoods were lowered so that the users could reach them. The heights of the ventilation hoods in the five kitchens are listed in Table 3.6. Kitchen No. 1 No. 2 No. 3 No. 4 No. 5 Height of the switches/sockets 145cm 150cm 145cm 115cm 120cm Owner’s comment Unreachable Unreachable Unreachable Reachable Reachable Table 3. 6: Heights of the ventilation hoods. The sockets and switches on the wall behind the countertop were very difficult to reach by all the wheelchair users. They were often highly installed, and because of the countertop beneath them, a wheelchair user could not get close to them. As a result, they became impossible to reach. 3.2.5. Washing Machine and Clothes Drying In the five houses, all the washing machines were placed in the kitchen. In fact, it is common for laundry to be done in the kitchen in HDB flats. However, because all the washing machines were top-loaded, the openings were too high for the wheelchair users to take the washed clothes out of the washing machines. Therefore, the wheelchair users did not use them. Most Singapore residents in HDB flats use bamboo poles to hang wet clothes out through the window for drying. However, it was impossible for the 5 wheelchair users to do so. The clothes hanging devices inside the kitchens were also too high for the wheelchair users to reach. 3.3. Floor Plan of the Five Kitchens All the five kitchen floor plans were mapped and the main dimensions were measured. Figure 3.1 is the floor plan of Kitchen No. 1. The area between the countertops was enough for a wheelchair to turn. The countertop was L-shaped but the leg of the “L” for placing sink was not long enough. The place of the refrigerator was not easy for a wheelchair user to access 15 because the refrigerator door could not be fully opened. As for Kitchen No. 2, the owner commented that she felt troubled to move her wheelchair round the washing machine when entering the kitchen from the living room (Figure 3.2). In Kitchen No. 3, the refrigerator was not very accessible because it was placed at the corner and the door could not be fully opened (Figure 3.3). Figure 3. 1: Floor layout plan of Kitchen No. 1 (unit: m) (R- refrigerator). Figure 3. 2: (Left) floor layout plans of Kitchens No. 2 (unit: m) (R- refrigerator; WM- washing machine). Figure 3. 3: (Right) floor layout plans of Kitchens No. 3 (unit: m) (R- refrigerator; WM- washing machine; T- table). Figures 3.4 and 3.5 are the floor plans of the two modified kitchens. The walls in both kitchens were removed for a more accessible room. In Kitchen No. 4 (Figure 3.4) the wall between the kitchen and balcony was removed because the kitchen area was constrained. Before the modification, the kitchen was 7.53m2 and it was too small for its owner. After the modification, the area was 14.9m2 by incorporating the balcony. Then the refrigerator and the washing machine could be placed on the balcony. The doors between the kitchen and bathroom were also removed to create a wider passage. 16 In Kitchen No. 5 (Figure 3.5), the wall between the kitchen and the living room was removed too. A wide ramp was built since the kitchen floor is lower than the living room. Both the owners were very satisfied with the modification of the walls. The findings of the observations were tabulated in Table 5.9 (p 70-72) for a comparison. Figure 3. 4: (Left) floor layout plan of Kitchen No. 4 (unit: m) (R- refrigerator; WMwashing machine; T- table). Figure 3. 5: (Right) floor layout plan of Kitchen No. 5 (unit: m) (R- refrigerator; WM- washing machine; T- table). 3.4. Summary It was found that the barriers observed in the Singapore home kitchens are similar to those found in the literature review related to Western wheelchair users. Barriers for wheelchair users in kitchens can be classified into two categories: those related to the vertical design and those related to the design of the floor layout. The barriers related to the vertical design exist in: a) the changed floor level; and b) improper height of countertop, cabinet, switches/outlets and appliances. The barriers related to the floor plan design exist in: a) improper location and width of door; b) insufficient space for a wheelchair; c) lack of knee space under countertop, sink, cooker, etc.; and d) an improper kitchen countertop layout. In the experiment, the above issues were re-addressed, physically tested and verified with findings from the literature. 17 CHAPTER IV. VERTICAL DESIGN OF KITCHENS As discussed in Chapter III, the primary barriers for wheelchair users in a kitchen were classified into two categories: those related to vertical design and those related to floor plan design. In this chapter, the vertical design of kitchens is discussed. In a kitchen, the heights of countertop, appliance, cabinet, and switches/outlets are closely linked to the user’s body dimensions and their reach. The studies (Floyd, et al., 1966; Jarosz, 1996; Stoudt, 1981; Wright, et al. 1997) showed that the anthropometry of people without disabilities simply does not reflect the size, reach, and strength data of persons with disabilities. However, there is lack of information on the anthropometry of the wheelchair users in Singapore. Though three anthropometric studies were conducted in 1985, 1988, 1995 (Lim et al. 1986; Ong et al. 1988; Singh et al. 1995), none of the samples included the wheelchair users. Therefore, a pilot study on anthropometric dimensions of wheelchair users in Singapore was conducted. This pilot study examined the approximate reaches of Singapore wheelchair users and their body dimensions. As Western data could not be directly applied to the local context and no recommendations on some important reaches and body dimensions were available in the local guidelines, this anthropometric study at least provided more suitable recommendations on the vertical design of the mock-up test kitchens. Anthropometry principles were applied to data collection and analyses (for details of the principles please see Appendix 5: Anthropometry Principles). 18 4.1. Subjects The study was carried out at the HWA in Singapore. All the subjects were the clients of the HWA who attended the physiotherapy and sports training in HWA once or twice a week. 16 male and 16 female wheelchair users were measured. In order that the small sample size in this study can be representative of the wheelchair users in Singapore, three criteria for subject selection had to be met: (1) their age distribution should be even; (2) their ethnic distribution should be according to the proportion of the population in Singapore; (3) their health conditions should comprise most of the symptoms. The distributions are listed in Table 4.1, 4.2 & 4.3. Number of Subjects Age (years) Male Female 20-30 3 3 30-40 4 3 40-50 3 4 50-60 60-70 3 3 3 3 Table 4. 1: Age distribution of the subjects. Number of Subjects Male 13 2 1 0 16 Ethnic groups Chinese (76.7%)* Malay (13.9%)* Indian (7.9%)* Other (1.5%)* Total Female 13 2 1 0 16 Table 4. 2: Ethnic distribution of the subjects. (* the ethnic proportion is according to Singapore Department of Statistics (2002)). Health conditions Cerebral Palsy Neurological Disorder Hemiplegia Head Injury Paraplegia Amputee Rheumatoid arthritis Chronic Neurological Condition Number of Subjects Male 1 2 3 2 4 2 1 Female 2 1 4 1 4 2 1 1 1 Table 4. 3: The health conditions of the subjects. 19 4.2. Method for Taking Measurements Six types of reach for each wheelchair user were measured. These measurements were chosen because they were most likely to be used for the barrier-free kitchen design. They were: (1) upward reach; (2) up-forward reach to a wall; (3) down-forward reach to a wall; (4) downward reach laterally; (5) forward reach over a table; (6) lateral reach over a table. No detailed method was found on how the anthropometry of wheelchair users determines the kitchen dimensions. Only some illustrations show the relationships between the reaches of the wheelchair users and the kitchen dimensions. Based on these illustrations, the important reaches were selected for measurement. Table 4.4 (p 22-23) shows the original illustrations and the corresponding reaches which were measured. In each type of reach, both comfortable reach and maximum reach were measured. The definitions of the comfortable and maximum reach were given by Floyd et al. (1966) in their anthropometric research about the wheelchair user’s reach. “A comfortable reach was defined as one in which the erect sitting posture was maintained, and only the reaching arm was moved. Whereas in determining the maximum reach, any body movements were allowed provided that the subjects remained in contact with the seat” (Floyd, et al., 1966, p27). Since the time available for measuring was limited, (the clients stayed at HWA for only a short time, and they had to attend training activities), the reaches were measured only on their better functional arm. A measuring board was used to indicate the reaching distances. The grid unit was centimeter. Because when a wheelchair user is cooking, he/she is usually required to grasp cooking tools, bowls and other utensils rather than to touch them, the grasp reaches were measured. 20 When a subject making a reach, he/she held a wooden stick and pointed it against the board. Simultaneously, the surveyor observed the position of the stick in order that it was perpendicular to the measuring board. Thus the correct distance was read. For details about the measurement methods please see Appendix 6: Methods for Measuring the Reaches. Besides the six types of reach, the knee heights as well as the wheelchair armrest heights were collected. These two heights were chosen because they are closely related with the countertop height. 4.3. Data Statistics The data obtained from the 16 male and 16 female subjects were statistically analyzed with the program “SPSS”. Means, standard deviations, variance, range, 5th, 50th and 95th percentile values were calculated (For details please see Appendices 7, 8, 9 & 10). A commonly accepted rule is that the designer should try to accommodate at least 90 percent of his population. In order to accommodate 90 percent of a group, the 5th to 95th percentile should be designed for. The extreme values represent chance occurrence which should be disregarded in design. Removing 5 per cent at both ends of the range will eliminate most of these “freak” values and leave a range covering 90 percent of the population. It is applicable when the population is large. In a large group, for example, the whole population of the wheelchair users in Singapore, it may be unrealistic and uneconomical to accommodate the spread from least to greatest value encountered in the group. However, for this study on the wheelchair users’ reaches, the selected sample size was small (only 32 persons totally). In order to secure that the estimation would be suitable for more wheelchair users, estimation was made based on the minimum reach of the subjects. The measurement results are shown in the Table 4.4. 21 Observations in the 5 kitchens Illustration figure Dimensions recommended in literature Dimensions measured or calculated Measurement result Ventilation hood (applied to the mock-up kitchens which were designed and tested) Upward reach is 150-170cm (Fingertip reach) Two subjects could reach the ventilation hood (at the heights of 115cm and 120cm) Three subjects could not reach (at the heights of 145cm, 145cm, & 150cm) Applications Upward reach (Left: Max; Right: Com.) (Source: Grandjean, 1973) Max: 135cm; Com: 128cm According to Stratton (2001): Up-forward reach is 122cm (Fingertip reach) Down-forward reach is 38cm (Fingertip reach) (Source: Stratton, 2001) Handles of doors/drawers, switches/outlets, shelves, etc. (applied to the mock-up kitchens which were designed and tested). Up-forward reach to a wall (Left: Max; Right: Com.) According to Building and Construction Authority (2002): Up-forward reach is 120cm (Fingertip reach) Down-forward reach is 40cm (Fingertip reach) The lower part of the cabinet was difficult to reach by all the subjects. Up-forward reach: Max: 121cm; Com: 110cm Down-forward reach: Max: 35cm; Com: 42cm Down-forward reach to a wall (Left: Max; Right: Com.) (source: Building and Construction Authority, 2002) Handles of the lowest drawers (applied to the mock-up kitchens which were designed and tested) Downward reach laterally is 25cm The corner cabinet and the lowest drawer were difficult to reach by all the subjects. (Source: Building and Construction Authority, 2002) Downward reach laterally (Left: Max; Right: Com.) Max: 32cm; Com: 41cm 22 Observations in the 5 kitchens Illustration figure Because in the five kitchens no knee space was provided under the counter, such kind of reach was not observed. Dimensions recommended in literature Dimensions measured or calculated Measurement result Applications Forward reach is the 50cm Forward reach over a table (Left: Max; Right: Com.) (Source: Building and Construction Authority, 2002) (The table is at height of 86cm) Max: 50cm; Com: 43cm A free-standing countertop shelf unit can be used (Source: Barrier Free Environments, Inc., 1991) Lateral reach over a table is 50cm, the table is at the height of 86cm) The cooking tools on the wall behind the countertop were hard to reach by all the subjects. The depth of the countertop was 60cm. Lateral reach over a table (Left: Max; Right: Com.) (Source: Building and Construction Authority, 2002) Wall cabinet Two subjects felt the countertop too high (at the height of 88cm and 89cm). Two subjects felt suitable (at the height of 75cm & 85cm). One subjects felt a little high (at the height of 85cm). Wall cabinets (applied to the mock-up kitchens which were designed and tested) Not available The wall cabinets were difficult by all the subjects (at the heights more than 134cm). The height of the wall cabinet bottom was calculated based on the maximum and comfortable reach over a table. Countertop height (Peterson, 1998) (The table is at height of 86cm) Max: 50cm; Com: 41cm The countertop height should be decided by the wheelchair user’s knee height, the thickness of the sink or cooker as well as the wheelchair armrest height. Knee height and wheelchair armrest height were measured. When a wheelchair user sits in a “desk arm” or “sport model” wheelchair, the countertop height can be estimated as his/her knee height plus a clearance between the knee and the counter’s bottom and 15cm for the counter’s thickness. When the wheelchair user sits in a “standard arm” wheelchair, the countertop height should be the armrest height plus a clearance between the armrest and the counter’s bottom and 15cm for the counter’s thickness. Max: 116cm; Com: 106cm Based on the knee height range, the countertop height should be largely from 70cm to 85cm. Based on the armrest height range, the countertop height should be largely from 75cm to 90cm. Countertop height (three heights, 75cm, 80cm and 85cm, were applied to the mock-up kitchens which were designed and tested). Table 4. 4: Comparison between the observations, illustrations, measurement results and their applications (Max- Maximum reach; Com- Comfortable reach). 23 4.4. Measurement Results and Discussion 4.4.1. Upward Reach The measurement results of the upward reach show that for the maximum reach, the minimum value is 135cm. The minimum value of the comfortable reach is 128cm. One of the barriers identified in a kitchen for a wheelchair user is that the ventilation hood’s switches are too high. Based on the measurement results of the upward reach, the reasonable height for the hood should be less than 135cm. The top part of a common refrigerator is often a freezer. According to the Barrier Free Environments, Inc. (1991), 50% of the freezer volume should be within reach of a wheelchair user (Figure 4.18). On the basis of the measurement results, if the freezer is seldom used by a wheelchair user, the middle height of the freezer could be about 135cm. If the freezer is frequently used by the wheelchair user, then the middle height of the freezer should be about 128cm because most of the wheelchair users can reach such height comfortably. Figure 4. 1: Freezer in the wheelchair user’s reach (Source: Barrier Free Environments, Inc., 1991). 24 4.4.2. Up-forward Reach to a Wall The measurement results of the up-forward reach to a wall show that for the maximum reach, the minimum value is 121cm. For the comfortable reach, the minimum value is 110cm. The results are approximately consistent with the recommendation in Singapore Guidelines. According to the Singapore Guidelines, without obstruction, the maximum forward reach is 1200mm from the floor (please see Table 4.4, p 22-23). Because the reach is not grasp reach in the Singapore Guidelines, then it could be estimated that the grasp reach should be less than the 1200mm. The value is likely between the measured minimum values of the maximum reach (121 cm, grasp reach) and the comfortable reach (110cm, grasp reach). Based on the measurement results, the door handles, switches, shelves and other objects alike should be installed at the height less than 121cm. For the frequently used appliances, the heights should be less than the 110cm, the minimum value of the comfortable reach. 4.4.3. Down-forward Reach to a Wall The measurement results of the down-forward reach to a wall show that for the maximum reach, the maximum value is 35cm. For the comfortable reach, the maximum value is 42cm. These results are approximately consistent with the recommendation in the Singapore Guidelines. According to the Singapore Guidelines, without obstruction, the minimum forward reach is 400mm from the floor (please see Table 4.4, p 22-23). Because this reach is fingertip reach, it could be estimated that the grasp reach should be slightly higher than the 400mm. The value is likely to be around the measured comfortable reach (42cm). Based on the measurement results, the handles of the drawers in the base cabinet, switches/outlets, shelves and other objects alike, should be installed at the height more than 35cm. For the frequently used appliances, the heights should be more than 42cm, at which height most of the wheelchair users can reach comfortably. 25 4.4.4. Downward Reach Laterally The measurement results of the downward reach laterally show that for the maximum reach, the maximum value is 32cm. For the comfortable reach, the maximum value is 41cm. These results are not very consistent with the recommendation in Singapore Guidelines. According to the Singapore Guidelines, without obstruction, the minimum downward reach laterally is 250mm from the floor (please see Table 4.4, p 22-23). Because this reach is fingertip reach, it could be estimated that the grasp reach should be a little higher than the 250mm. Furthermore, the measurement results suggest that the handles of the drawers in the base cabinet, switches/outlets, shelves and other objects alike should be installed at the height more than 32cm. For the frequently used appliances, the heights should be more than 42cm, at which height most of the wheelchair users can reach comfortably. Table 4.5 shows the maximum values of the down-forward reach to a wall and downward reach laterally. The two measurements indicate that the handles, switches, shelves and other objects alike, should be installed at the height more than 35cm. For the frequently used appliance, the height should be more than 42cm. Total Maximum reach Down-forward reach to a wall 35cm Downward reach laterally 32cm Comfortable reach 42cm 41cm Table 4. 5: Values of the down-forward reach to a wall and downward reach laterally. 4.4.5. Forward Reach over a Table The measurement results of the forward reach over a table show that for the maximum reach, the minimum value is 50cm. It can also be calculated that the 25th percentile of the wheelchair users are able to reach the 60cm (the calculation method please see Appendix 5: Anthropometry Principles). It means that about 24 percent of the wheelchair users cannot reach the back wall behind a countertop, considering 60cm for the depth of the countertop. 26 The minimum value of the comfortable reach is 43cm. The maximum value of the comfortable reach is 55cm. It means that for most wheelchair users, the objects placed on the wall behind the countertop are out of their comfortable reach range, considering 60cm for the depth of the countertop. The measurement results supported the viewpoint that “reaching over a counter to the back wall is difficult for most seated people” (Barrier Free Environments, Inc., 1991, p112). Therefore, different from a common kitchen, cooking tools such as pancake turners, knives, clamps etc. should not be hung on the back wall in a kitchen for wheelchair users. A free-standing countertop shelf unit between countertops and the bottom of the wall cabinet can be easily reached by a wheelchair user (please see Table 4.4, p 22-23). The cooking tools which are hung on the back wall in a common kitchen can be stored in this kind of shelf. The measurement result is also largely consistent with the recommendation of the Singapore Guidelines. According to the Singapore Guidelines, the maximum forward reach over an obstruction is 500mm maximum (please see Table 4.4, p 22-23). Because in the Singapore Guidelines the reach is fingertip reach, it could be estimated that the grasp reach should be a little less than the 500mm. The value is likely between the measured minimum values of the maximum reach (50cm) and the comfortable reach (43cm). Based on the maximum and comfortable reach over a table, the maximum height of the wall cabinet bottom can be approximately estimated. This estimation assumes that adequate knee space is provided under the counter. 27 Figure 4. 2: Estimation of the wall cabinet height. Illustrated in Figure 4.2, it is already known that the minimum value of the maximum reach over a table is 50cm, the countertop depth is 60cm and the horizontal distance between the edge of the countertop and the edge of the wall cabinet is 30cm (the wall cabinet in common use is usually 30cm in depth). Assuming that the arm’s pivot holds still and the arm rises up to reach the wall cabinet, then the length of the hypotenuse of the right-angled triangle (drawn as thick lines in the Figure 4.2) is 50cm. Then h = 50 2 − 30 2 = 40 cm (according to the Pythagorean proposition). Because the table height is 86cm, then the height of the wheelchair user’s reach is 126cm (86cm+40cm). For wheelchair users, the items stored in the wall cabinets should be small. If the items are big, it could be difficult and dangerous for a wheelchair user to take them off the wall cabinet. Therefore, big items are left out of account. If 10cm is assumed as the average height of the small items, then the height of the wall cabinet bottom should be 116cm at maximum (clear knee space should be under the counter). Based on the minimum value of the comfortable reach over a table (43cm), the maximum height of the wall cabinet can be calculated too. The h = 432 − 30 2 = 30.8 cm. If 10cm is assumed as the average height of the small items, then the height of the wall cabinet bottom should be 106cm (clear knee space should be provided under the counter). 28 4.4.6. Lateral Reach over a Table The measurement results of the lateral reach over a table show that for the maximum reach, the minimum value is 50cm. The minimum value of the comfortable reach is 41cm. Similar to the forward reach over a table, the results show that for most wheelchair users, the objects placed on the wall behind the countertop are difficult to reach. The measurement results of the lateral reach over a table are also largely consistent with the recommendation of the Singapore Guidelines. According to the Singapore Guidelines, if there is an obstruction, the maximum lateral grasp reach over an obstruction 860mm high is 500mm horizontally and 1200mm vertically from the floor (please see Table 4.4, p 22-23). Table 4.6 shows the minimum values of the forward reach over a table and lateral reach over a table. The two measurements suggest that the cooking tools should be located within the range of 50cm over a countertop. The frequently used tools should be located within the range of 41cm over a countertop. Total Lateral reach over a table Maximum reach Forward reach over a table 50cm Comfortable reach 43cm 41cm 50cm Table 4. 6: Values of the forward reach over a table and lateral reach over a table. 4.4.7. Knee Height, Wheelchair Armrest Height and Countertop Height The measurement results of the knee height of the wheelchair users are listed in Table 4.7. 29 Minimum Maximum Mean Accuracy SD. 5th 50th 95th Male 57.0 70.0 64.1 ±1.84 3.67 57.0 65.5 70.0 Female 53.0 68.0 60.2 ±2.15 4.29 53.0 60.0 68.0 Total 53.0 70.0 62.2 ±2.21 4.41 53.7 62.5 68.7 Table 4. 7: Measurement results of the knee height. The knee height is highly correlated with the height of the working surface for wheelchair users. According to the NKBA Guidelines (Peterson, 1998), the countertop’s heights are mainly decided by the wheelchair user’s knee height, the thickness of the sink or cooker as well as the wheelchair armrest height (Figure 4.3). Figure 4. 3: The countertop height is decided by the appliance thickness, knee height and armrest height. When the 32 wheelchair users’ reaches were measured at HWA, the armrest heights of the wheelchairs were also measured. The distribution is listed in Table 4.8. The result is approximately consistent with the Singapore Guidelines. According to the Singapore Guidelines, the maximum wheelchair armrest is around 76cm high. Total Minimum Maximum Mean Accuracy SD. 5th 50th 95th 58.0 75.0 68.9 ±2.02 4.03 61.9 69.0 75.0 Table 4. 8: Measurement result of the wheelchair armrest height. 30 The measurement of the 32 wheelchair users’ knee heights and the armrest heights shows that the wheelchair’s armrests are higher than the wheelchair users’ knee. If the countertop height is determined by the armrest height plus the thickness of the appliance, it could be too high for a wheelchair user. For example, according to Peterson (1998), the knee space preferred is 29” (74cm) to clear wheelchair armrests for most people. If a sink is about 15cm in thickness, then the total height of the countertop will be 89cm. This height is much higher than the preferred countertop height for most seated user (81cm according to Peterson (1998)). This problem may be settled by the “step-designed counter” (Figure 4.3). The appliance is installed a little distance apart from the countertop edge; thus, the armrest can be under the counter, and the bottom of the appliance can be lower than the armrest. Another solution is to choose a different wheelchair type (Figure 4.4). “Desk arms” and “sport model arms” will require less knee space clearance and will fit under lower counters. When designing a kitchen for a particular wheelchair user, determination of the type of wheelchair may allow more flexibility in setting heights and clearances. Figure 4. 4: Different types of the wheelchair. (Source: Barrier Free Environments, Inc., 1991) According to Peterson (1998), the thickness of the sink for wheelchair user are usually 5”-6 ½” (13cm-17cm). Other literatures also recommend that the sink’s thickness should be in this range (British Standard Institution, 2000; Barrier Free Environments, Inc., 1991; The Board of the Registration of Architects, 2002). Therefore, 13-17cm was used as the sink’s thickness in this study for estimations and designs. 31 No specific recommendations could be found on the cooker’s thickness for the wheelchair users through the literature review or web search. Therefore, the normal cooker’s dimensions were checked on the Haier home production list and the production of some other enterprises (Haier Group Company, 2003; CNBMB, 2003). The Haier home production list was selected because the Haier Group Company is one of the largest enterprises in Asia where kitchen appliances are produced. The check indicated that most of the cooker’s thicknesses are less than 15cm. The mean knee height of the 32 wheelchair users is 62.2cm. If a wheelchair user with the mean knee height sits in a wheelchair which is a “desk arm” or “sport model” type, the base of the countertop can be set at 65cm high considering a clearance around 3 cm between the knee and the counter base. The thickness of the counter should be at least 15cm for installing the cooker and sink. Therefore, the countertop height is 80cm (62.2cm + 3cm + 15cm). If he/she sits in a “standard arm” wheelchair of which the armrest is 70cm, then the countertop should be at the height of 85cm (70cm + 15cm). Based on the knee height range (from 53cm to 70cm), adding the thickness of the counter (15cm), the countertop height should be approximately from 70cm to 85cm. Based on the wheelchair armrest height range (from 58cm to 75cm), the countertop height should be approximately from 75cm to 90cm. Application: Three heights (75cm, 80cm and 85cm) were applied to design the mock-up test kitchens. The countertop in each mock-up test kitchen could be set at these three heights. The subjects chose their favorite heights to do the tests. 32 Besides the main countertop, some small ancillary countertops can be installed below the main countertop to meet the wheelchair user’s different needs (Figure 4.5). For the details about the discussion on the knee height, please see Appendix 11: Knee Height. Figure 4. 5: Small ancillary countertops below the main countertops. 4.4.8. Summary of the Reach The illustrations of the measurement results are shown in Table 4.4 (p 22-23). Based on the measurement results of the wheelchair user’s reach, all the recommendations discussed before are listed in Table 4.9. Horizontal reach over a countertop (the forward reach and lateral reach result were combined) Bottom of wall cabinets Ventilation hood Middle height of the refrigerator, Handles of doors/drawers, switches/outlets, shelves, etc. Countertop height Maximum reach range ≤50cm Comfortable reach range ≤41cm ≤116cm ≤135cm ≤135cm 35cm~120cm ≤106cm ≤128cm ≤128cm 42cm~110cm Determined by the wheelchair user’s knee height, wheelchair armrest height and the appliance thickness. The countertop height varies according to different users. Table 4. 9: Recommendations for the kitchen design for wheelchair users. Application: All these reach ranges were applied to the vertical design of the mock-up test kitchens. 4.5. Accessible Cabinets In the investigated kitchens, the corner cupboards are difficult to use for the wheelchair users because they are difficult to reach. Application of a rotating cabinet (or called “Corner Lazy Susan”) could increase access to the interior of the cupboard at the corner. “Full-extension drawers” can make the total volume of base cabinet space accessible to most users (Barrier33 free Free Environments, Inc., 1991). For details of the rotating cabinet and the “full-extension drawers” please see Appendix 12: Accessible Cabinets. Application: In the mock-up test kitchens the rotating cabinets were designed at the corner. Because the kitchen mock-ups were made of cardboard, the “full-extension drawers” were unable to be built. Thus only normal drawers were built instead. 4.6. Clothes Washing and Drying There are two types of washing machines: top-loaded (Figure 4.6 Left) and front-loaded (Figure 4.6 Right). The top-loaded model is not suitable for wheelchair users as in this type wheelchair users have to lift their clothes high before they can put them in it as well as take them out. Compared with top-loaded models, front-loaded models are easy for moving clothes. Besides, the front-loaded washing machine can be raised from the floor to meet the wheelchair user’s reach. Therefore, the front-loaded washing machine is recommended. The door bottom of the washing machine should be in the reach range of the wheelchair user (35cm~120cm for maximum reach and 42~110cm for comfortable reach). Figure 4. 6: (Left) top-loaded washing machine. (Right) front-loaded washing machine. The preferred method for clothes drying in most HDB flats is not suitable for wheelchair users. A new device for clothes drying (Sxshaiyiqi, 2003) is recommended here. Figure 4.7 34 is an example of the device. One advantage of this new device is that by rotating the handle of the device below on the wall, the level pole of the device can be easily lowered at any height. After hanging clothes on the pole, a wheelchair user can also raise the pole again by rotating the handle. The device is also not expensive. Figure 4. 7: Device for easy clothes drying (Source: Sxshaiyiqi, 2003). Application: In the mock-up test kitchens the front-loaded washing machine was used. 35 CHAPTER V. FLOOR PLAN DESIGN OF SMALL KITCHENS FOR WHEELCHAIR USERS In Chapter III, the barriers for wheelchair users in a home kitchen are classified into two categories: those related to vertical design and those related to floor plan design. In Chapter IV, the vertical design is discussed. This chapter mainly discusses the floor plan design of the HDB kitchens. First, before the layout analyses were conducted on the HDB kitchens, five basic dimensions were discussed. They were: (1) approaching spaces at doors; (2) turning space for wheelchair users; (3) Minimum width of the different kitchen layouts; (4) minimum width of a wall with doors; (5) clear floor space for a wheelchair user at appliances. Secondly, a kitchen database was set up and 28 kitchens were selected for the graphic analyses. Criteria for the graphic analyses were also set. Finally, the 28 kitchens were analyzed by considering the following: (1) Basic area requirement; (2) kitchen shape; (3) place of sink and cooker; (4) place of refrigerator; (5) place of washing machine and clothes drying. 5.1. Dimensions for Graphic Analysis Five basic dimensions for wheelchair users were set for later schematic analysis. The dimension settings for a wheelchair user were derived from three sources: Singapore Guidelines, NKBA Guidelines and ADA Guidelines. Among the three guidelines, Singapore Guidelines is the only one which provides guidelines for local accessible designs. But it lacks detailed guidelines for kitchen designs. NKBA Guidelines is compiled by the National Kitchen & Bath Association in USA (NKBA). ADA 36 Guidelines, a set of compulsory guidelines for accessible design in the USA, is used as a reference too. In NKBA and ADA Guidelines, the guidelines which are closely related to body dimensions cannot be applied directly in Singapore because of their Western context. Any mismatch can result in poor use. These guidelines must be revised when applying them in Singapore. In a kitchen, such dimensions include the countertop height, knee space height, cabinet height etc. The guidelines in Singapore guidelines were mainly used when designing the kitchen layouts. Yet on certain aspects of kitchen design, no recommendation could be found in the Singapore Guidelines. Thus the corresponding Western guidelines were consulted as a reference. There were two places where the Western guidelines were used. The first place was the approaching spaces to a swing door. The approaching spaces had been tested (for details please see Section 5.1.1.2: Approaching spaces at doors) before they were used for floor analysis. The second place was the minimum countertop spaces beside the cooker and sink. Because the countertop spaces beside the cooker and sink are mainly determined by the usage of the appliance itself, they were applied for estimation of the minimum length of the leg of the L-shaped layouts (For details please see Appendix 15: Minimum Width of the Different Kitchen Layouts, 3: Lshaped Kitchen). 5.1.1. Approaching Spaces at Doors There are three types of doors usually used in home: a swinging door, a sliding door or a folding door. For more details of this section please see Appendix 13: Approaching Spaces at Doors. 37 5.1.1.1. Door width The Singapore Guidelines recommends that “minimum clear opening of doorways shall be 900mm measured between the face of the door stop with the door open at 90 degrees. Both for swing doors and sliding/folding doors”. The NKBA Guidelines recommends 810mm and The ADA Guidelines recommends 815mm for the clear opening. Because the Singapore Guidelines is a local code and a wider door opening provides more accessible way for wheelchair users, 900mm was adopted in this thesis for schematic analysis and design of the mock-up test kitchens. 5.1.1.2. Approaching spaces at doors The maneuvering space for a wheelchair user turning through a door is determined by both the opening width of the door and the space available for approaching the door (Peterson, 1998, p12). According to the Singapore, NKBA and ADA Guidelines, opening a door by a wheelchair user from the pull side takes more space than from the push side. In order to simplify the analysis of the HDB kitchen floor plans, it is assumed that swing doors are used in a kitchen and the doors should be opened outwards from the kitchen. Because the living room is usually larger than a kitchen, it is reasonable and acceptable that a door’s pull side is in the living room and the push side is in the kitchen. However, it may be improper when a door swings outwards to a bathroom/balcony because the bathroom/balcony is often small. In this situation, a sliding/folding door can be used instead. The reason is stated in the next two paragraphs. From the push side, there are three approaching methods to a swing door and three methods to a sliding/folding door in the guidelines. They are shown in Figure 5.1. 38 (1) front approaches to a swinging door (push side, according to Singapore Guidelines) (4) front approaches to a sliding/folding door (according to NKBA Guidelines) (2) hinge-side approaches to a swinging door (push side, according to NKBA Guidelines) (3) latch-side approaches to a swinging door (push side, according to NKBA Guidelines) (5) sliding-side approaches to a sliding/folding door (according to NKBA Guidelines) (6) latch-side approaches to a sliding/folding door (according to NKBA Guidelines) Figure 5. 1: Different approaching methods at doors. By comparing the approaching methods between (1) and (4), (2) and (5), (3) and (6), it was found that the approaching space for a sliding/folding door is smaller than a swing door correspondingly. Thus if a swing door can be accessed by a wheelchair user in the first three recommended spaces, a sliding/folding door will be accessed instead. 5.1.1.3. Tests at HWA Simple tests were conducted on the first, second and third approaching methods at HWA. Five male and 5 female wheelchair users in different healthy conditions were selected to take part in the tests. Three doors were selected and the approaching space boundaries were drawn on the ground (Figures 5.2, 5.3 & 5.4). Each wheelchair user was asked to access the three doors inside the space boundaries and the time was recorded. The test results are shown in Table 5.1. 39 Health condition M1 M2 M3 M4 M5 F1 F2 F3 F4 F5 Paraplegia Amputee Amputee Hemiplegia Arthritis Amputee Paraplegia Neurological disorder Hemiplegia Hemiplegia Time for approaching doors (in seconds) First method Second method 10 16 7 13* 8 9* 17 22* 17 24* 9 15 15 23* 18 27* 10 15 8 17* Third method 17 13 10 20 24 14 23 25 14 16 Table 5. 1: Time spent in different methods (* indicates that the subjects needed more space in the second method). The tests showed that for the first (Figure 5.2) and third (Figure 5.3) approaching methods to a swing door, all the wheelchair users could access the doors, though the time they took differed greatly. Wheelchair users who were paraplegia or amputee took less time because they had better upper body functions. On the other hand, those who had hemiplegia, arthritis or neurological disorder etc. took a longer time as they were weak. (1) (2) (4) (5) (3) Figure 5. 2: The first approaching method (front approaches to a swinging door at push side). 40 (1) (2) (4) (5) (3) Figure 5. 3: The third approaching method (latch-side approaches to a swinging door at push side). However, for the second approaching method (Figure 5.4), it showed that some wheelchair users needed more space than that recommended by NKBA Guidelines. (1) (2) (4) (5) (3) Figure 5. 4: The second approaching method (hinge-side approaches to a swinging door at push side). Figure 5.5 shows a wheelchair user opening a door. She approached the door in the second method. Because she could not bend her body very far ahead, in order to reach the door handle, she drove her wheelchair very near to the handle. Thus the wheelchair’s fore-wheel was beyond the line. The same cases occurred on 6 other wheelchair users. Therefore, it is recommended that more space be provided at the latch side of the door. 41 Figure 5. 5: Wheelchair’s fore-wheel was beyond the line. In the first approaching method, the space beside the latch side of the door is recommended as minimum 30cm (please refer to Figure 5.1 (1)). Therefore, if 30cm wide space (shaded area in Figures 5.5 right & 5.6) is added to the second approaching method on the latch side of the door, it will be more accessible. Figure 5. 6: More space is needed on the latch side of the door. Application: The dimensions of the approaching space at doors were applied to the mock-up test kitchens. For details please see Chapter VI, Sections 6.1 & 6.2. 5.1.2. Turning Space for Wheelchair Users For wheelchair users there are two types of turn: circle turn and T-turn. The recommendations from the three guidelines are listed in Table 5.2 (for more details please see Appendix 14: Space for Wheelchair Turning). 42 Circle turn T-turn Singapore Guidelines NKBA Guidelines 1800mm (diameter) 1520mm (diameter) Not available 91cm×91cm×152cm (minimum) 91cm×91cm×183cm (preferred) ADA Guidelines 1520mm (diameter) Not available Turning space under the countertop Not available If the knee is at least 122cm-137cm wide, 48cm of the 152cm turning space can be part of the knee space Not available Table 5. 2: Recommendations on the turning space. According to Julius Panero and Martine Zelnik (1979), when a wheelchair makes a turn based on moving wheels in opposite directions and pivoting about the center, the diameter for average turning space is about 160.0cm (63in). When a wheelchair makes a turn based on locking one wheel and turning the other with the pivot point on the locked wheel, the diameter for average turning space is about 182.8cm (72in) (Figure 5.7). The recommendation of the Singapore Guidelines allows a wheelchair turn when one wheel is locked (or just remains still) and the other turns. A wheelchair user who is only good on one body side may use this kind of turn. The recommendation of the NKBA Guidelines and ADA Guidelines allows a wheelchair to turn by moving the wheels in opposite directions and pivoting about the wheelchair’s center. This kind of turning requires the user with more care and use equal force on both wheels. Figure 5. 7: Turning radius based on different pivot points (Source: Panero & Zelnik, 1979). 43 5.1.2.1. Tests at HWA Simple tests were conducted at HWA on the circle and T-shaped turning space. The subjects were the same wheelchair users who had taken part in the tests on approaching spaces to doors. Figure 5. 8: (Left) turning in a small circle turning space. Figure 5. 9: (Right) turning in a large circle turning space. Figure 5.8 shows a subject turning in the small circle turning space (diameter is 1520mm, as recommended by NKBA and ADA Guidelines). Figure 5.9 shows a subject turning in the large circle turning space (diameter is 1800mm, as recommended by Singapore Guidelines). The small white columns put on the circle were used to identify the boundaries. A 360o turn was made by the subject and the time was recorded. Figure 5.10 shows a subject made a T-shaped turn. (1) (2) (4) (5) (3) Figure 5. 10: Turning in a T-shaped space. 44 The results of the tests are shown in Table 5.3. It can be seen that the time used for turning in the large circle was much less than that used for tuning in the small circle or T-shaped space. A small circle or T-shaped turning required a wheelchair user to be more capable to control his/her wheelchair. For those who were weak or only good on one hand, it was difficult to turn in these two kinds of spaces. Three of them could not fulfill a full turn in these two kinds of spaces. Health condition M1 M2 M3 M4 M5 F1 F2 F3 F4 F5 Paraplegia Amputee Amputee Hemiplegia Arthritis Amputee Paraplegia Neurological disorder Hemiplegia Hemiplegia Time for turn (in seconds) In the small circle In the large circle 35 9 9 6 13 8 26 20 Unable 26 15 11 20 15 Unable 25 37 14 Unable 30 T-shaped 32 15 19 40 Unable 19 30 Unable 40 Unable Table 5. 3: Time spent in three different turning spaces. Therefore, two concepts were introduced: the “Optimum small kitchen” and the “Minimum small kitchen”. An “Optimum small kitchen” is a kitchen that provides longer countertops (which allows large appliances installed), large turning space, more storage, etc. The word, “optimum” means though the kitchen is small, it is comfortable enough to be used by most wheelchair users. A “Minimum small kitchen” is a kitchen which provides shorter countertops (which only allows small appliances installed), small turning space, less storage, etc. The word, “minimum” means that though the kitchen can be used by a wheelchair user, it is less comfortable and, therefore, requires the wheelchair user to be in better body conditions. 45 There are at least three advantages in applying these two concepts: (1) A wheelchair user has two choices when he/she plans to buy a HDB flat. First, he/she may choose the Optimum small kitchen, which is used comfortably. Second, the Minimum small kitchen can be chosen because it costs less. (2) For designers, these two concepts require them to pay more attention to the users’ body capabilities. They will consider who will use the kitchens and whether they will use it comfortably. (3) For HDB, it is more flexible to apply these two types of kitchens. Some flats can be built with the Optimum small kitchens and others with the Minimum small kitchens based on the market needs. Application: In this thesis, both the recommendations of the Singapore Guidelines and the NKBA Guidelines for a wheelchair’s circle turn were used for the graphic analyses of the kitchen floor plans (for details please see Appendix 16: Minimum width of the different kitchen layouts). When the mock-up kitchens were designed and tested for qualitative studies, one kitchen was designed as an “Optimum small kitchen” to provide a large turning space. Two kitchens were designed as “Minimum small kitchens” to provide a small turning space. For details please see Chapter VI, Sections 6.1 & 6.2. 5.1.3. Minimum Width of the Different Kitchen Layouts There are mainly four types of kitchen plan: one-sided kitchen, two-sided kitchen, L-shaped kitchen, and U-shaped kitchen. Based on the dimensional requirements of wheelchair users, 46 the minimum widths of the four types of kitchen were deduced. For each type of kitchen, there were two situations estimated: (1) the clear circle turning space was provided beside the countertop; and (2) part of the circle turning space was under the countertop. Because the circle turning space could be large (according to Singapore Guideline) and small (according to NKBA and ADA Guidelines), there were four estimations for each type of kitchen. For details of this section please see Appendix 15: Minimum Width of the Different Kitchen Layouts. A summary is shown in Table 5.4. Application: The minimum widths for L-shaped and U-shaped kitchen were applied to design the mockup test kitchens for qualitative studies. For details please see Chapter VI, Sections 6.1 & 6.2. 47 Kitchen Type Layout According to Singapore Guidelines According to NKBA Guidelines L=240cm L=212cm Minimum width is 240cm Minimum width is 212cm L=192cm L=164cm Minimum width is 192cm Minimum width is 164cm L=300cm L=272cm Minimum width is 300cm Minimum width is 272cm L=252cm L=224cm Minimum width is 252cm Minimum width is 224cm One-sided Kitchen Two-sided Kitchen S=194cm (sink) L=240cm L=212cm Minimum width is 240cm Minimum width is 212cm S=194cm (sink) L=192cm L=164cm Minimum width is 194cm Minimum width is 194cm L-shaped Kitchen C= 181cm (cooker) L=240cm L=212cm Minimum width is 240cm Minimum width is 212cm C=181cm (cooker) L=192cm L=164cm Minimum width is 192cm Minimum width is 181cm L=300cm L=272cm Minimum width is 300cm Minimum width is 272cm L=252cm L=224cm Minimum width is 252cm Minimum width is 224cm U-shaped Kitchen Table 5. 4: The minimum width for different kitchen layouts. 48 5.1.4. Minimum Width of a Wall with Doors The width of a wall with doors needs to be considered. Figure 5.11 shows commonly used layouts in an HDB kitchen. The approaching space at a door for a wheelchair user is 1.2m×1.2m (front approach to a swinging door from the push side). The width for a counter (or a washing machine, or a refrigerator) is 0.6m. There are ten possible layouts. The minimum widths for these layouts were calculated based on the wheelchair users’ requirements. When designing a kitchen, these dimensions should be followed. Application: The layouts (2), (3) and (10) were applied to design the mock-up test kitchens for qualitative studies. For details please see Chapter VI, Sections 6.1 & 6.2. 49 ⑴ a swing door ⑵ a swing door + a countertop ⑶ a countertop + a small turning space ⑷ a countertop + a large turning space ⑸ a swing door + two countertops, with a small turning space (part of which is under a countertop) ⑹ two countertops + a large turning space (part of which is under a countertop) ⑺ two countertops + a small turning space (no part of which is under a countertop) ⑼ two swing doors + a countertop ⑻ two countertops + a large turning space (no part of which is under a countertop) ⑽ two swing doors + two countertops Figure 5. 11: Minimum width of the kitchen. 50 5.1.5. Clear Floor Space for a Wheelchair User at Appliances Recommendations about the clear floor space for a wheelchair user at appliances are listed in Table 5.5. For details of this section please see Appendix 16: Clear Floor Space for a Wheelchair User at Appliances. Clear floor space Sitting direction Singapore Guidelines 90cm×120cm NKBA Guidelines ADA Guidelines 76cm×122cm 76cm×122cm Parallel approach and perpendicular (forward ) approach Same as above Same as above Clear floor space under work surface 48cm deep 48cm deep 48cm deep Table 5. 5: Recommendations about the clear floor space. In this thesis, recommendations on the clear floor space at appliances given by the Singapore Guidelines and the NKBA guidelines were adopted for the graphic analysis of the kitchen floor plans. In fact, because the two recommendations were similar, the kitchen analysis results showed that there was no much difference between the analysis based on either the Singapore Guidelines or the NKBA Guidelines. Figure 5.12 shows the clear floor space at different appliances. 51 Figure 5. 12: A clear floor space at appliances (Source: Peterson, 1998). Application: The clear floor spaces at appliances were applied to design the mock-up test kitchens for qualitative studies. For details please see Chapter VI, Sections 6.1 & 6.2. 5.2. Setting up the Database of Kitchen and the Criteria for Graphic Analysis From the start, HDB adopted the principle that a flat is to be self-contained with its own kitchen and shower/toilet cum wash area (Wong and Yeh, 1985). By 1970, when the economy started to boom and living standards began to rise, a new series of prototype of three-room, 52 four-room and five-room flats in slab blocks were developed (Housing & Development Board, 1998). Two key principles were taken into account when the kitchen’s functional plan and dimensions were set. According to Wong and Yeh (1985), first, in order to accommodate the habits of the residents, the bathroom and laundry were generally kept to a corner of the kitchen; second, in small flats, the kitchen was preferred as a dining area. Thus, kitchen size and arrangement of the kitchen fittings such as sinks were considered to provide adequate area for a dining table and chairs. Because of these reasons, for families living in HDB flats, the laundries and eating are usually done in a kitchen. For more details of this section please see Appendix 17: Development of HDB Flats and Kitchens. 5.2.1. Setting up the Database of Kitchen During the last two decades, HDB has developed a range of different types of flats. Kitchens in these flats are not very big because of the flats’ limited area. In order to discuss the barriers in HDB kitchens from the aspect of floor plan, the prototypes of the HDB flats in the HDB Annual Report from 1978 to 1999 were collected for analysis. There are no detailed dimensions of the kitchen in the report; only main dimensions of the whole flats are provided. Based on the scales given (usually 1:100, 1:125 or 1:200), the dimensions of the kitchens were measured and the net areas (the walls are not included) were calculated. Since in this thesis, the main aim was not to critically judge the HDB kitchens, it was not necessary to know the accurate dimensions of the kitchens. These kitchens with approximate dimensions could provide proper and practical samples for kitchen layout analyses. From 1978 to1999, 99 kitchens (executive apartments were not included) appeared in the HDB Annual Report (HDB 1977-1999). Information for the 99 kitchens was put into the program Microsoft Access according to the following aspects: flat type, isomorphic shape, length, width, kitchen area and flat area. This database is shown in the Appendix 18: Kitchen Database. The 53 kitchen was numbered according the occurring year and sequence. For example, Kitchen 878801 indicates that the kitchen was recorded in HDB Annual Report 87-88, and the sequence number 01 means it was the first kitchen listed in the book. By providing different queries, Microsoft Access could classify the kitchens according to various requirements. For example, it could arrange all the kitchens according to increasing areas simultaneously listing out the flat type, length, width and isomorphic shapes (Table 5.6). Kitchen Area (m2) Serial Number Flat Type Length Width Isomorphic shape 5.5 5.5 6.67 7.54 8.3 9.57 9.57 9.57 … 7778-01 7980-01 9596-01 9596-02 8182-08 9495-01 9394-01 9394-02 … 1-room improved 1-room improved 4-room model “A” 5-room improved 3-room model “A” 4-room model “A” 4-room model “A” 5-room improved … 2.7 2.7 2.9 2.9 4.6 3.3 3.3 3.3 … 2.2 2.2 2.3 2.6 2 2.9 2.9 2.9 … s3 s3 s1 s1 s6 s1 s1 s1 … Table 5. 6: Microsoft Access can list data according to different enquiries (for details about the shape please refer to Chapter V, Section 5.3.2: Kitchen Shapes.) The kitchens less than 15m2 were selected for analysis. There were three reasons: (1) according to Peterson (1998), a small kitchen is equal or less than 14m2; (2) three barrier-free kitchens recommended in the literature (Scottish Development Department, 1979; Barrier Free Environments, Inc., 1991) are 8.64m2, 10.15m2 and 11.9m2. All are far less than the area of 14m2; therefore, a premise was set that a large kitchen (area over 14m2) was big enough for a wheelchair user to use; (3) in order to include more types of the HDB kitchen, finally the kitchens whose areas were less than 15m2 were selected for analyses. (For the details please see Appendix 19: Area Criterion for Choosing Kitchen). There were 28 different kitchens altogether from 1978 to 1999. All the kitchens are shown in Appendix 18: Kitchen Database. 54 5.2.2. Setting the Criteria for Graphic Analysis In the HDB Annual Report (HDB, 1977-1999) there were no illustrations of the appliances and countertop layouts for a kitchen. Therefore, the possible layouts of the kitchens were designed according to the following criteria: 1. Adequate space for a wheelchair to approach a door must be provided (according to Singapore Guidelines). 2. Clear floor space at appliances for a wheelchair user must be provided (according to Singapore and NKBA Guidelines). 3. The preferred location for a refrigerator is near the door to the living room (source: Kootz, 1994). 4. The preferred location for a washing machine is near the bathroom, or adjacent to a sink (source: Wong and Yeh, 1985; Kootz, 1994). 5. The refrigerator, sink and cooker should not be either too near or too far (source: Grandjean, 1973). 6. A turning space for a wheelchair must be provided (according to Singapore and NKBA Guidelines). In order to eliminate personal preferences and bias as much as possible, attempts were made to include all the possible layouts of the kitchens. Among the 28 different kitchens, 10 kitchens had two possible layouts. One kitchen (7879-01) had three possible layouts. There were total 40 different layouts designed. All the analyses of the kitchen plans are shown in Appendix 27: Kitchen Layout Analyses. 5.3. Floor Plan Analyses of the HDB Kitchens 5.3.1. Basic Area Requirement A kitchen for wheelchair users should have enough area for countertops, cabinets, appliances and the clear wheelchair moving space. According to the Scottish Housing Handbook (Scottish 55 Development Department (SDD), 1979), the area for a typical standard kitchen for a wheelchair user is about 8.64m2 (3600mm×2400mm), with a casual dining area outside the kitchen (Figure 5.13). Figure 5. 13: Kitchen layout to suit a wheelchair user (Scottish Development Department, 1979) (O – oven; H – hob; C – cooker; TS - trolley storage unit; B – broom cupboard; WM – washing machine; R – refrigerator; RS – rotating storage unit; S – sink). In the SDD typical kitchen, the appliances are similar to those in an HDB kitchen in Singapore. In a common HDB kitchen, usually the cooker, sink, refrigerator, washing machine are used, except the oven. Therefore, based on the recommendation given by the SDD, the assumption was made that an HDB kitchen area of about 9 m2 is the “Optimum” area for a wheelchair user. 5.3.1.1. Kitchen analyses The 40 layouts of 28 kitchens whose areas are less than 15m2 were analyzed. It was found that in kitchens smaller than 9m2 the layouts were somewhat problematic (e.g. Kitchens 7778-01; 9596-01; 9596-02; 8182-08). When the kitchen’s area was about 9m2, the layout was just suitable to be used (e.g. Kitchens 9495-01; 9394-03). As the area increased, the kitchen became easier to use. For details please see Appendix 20: Examples of Schematic Analysis about Kitchen Area. 56 The analysis showed that the area of an “Optimum small kitchen” seemed to be around 9m2 for a wheelchair user to perform basic kitchen tasks (only cooking and laundry). But this area was only correct when the kitchen shape was rectangular and had a proper kitchen width. This assumption was further confirmed by the mock-up testing. Compared with SDD typical kitchen (Figure 5.13) for a wheelchair, HDB kitchens have more doors to them. Usually at least two doors are opened: one to the living room and the other to the bathroom. Sometimes there is a third door to a balcony or a civil defense room. Thus, compared with SDD kitchen, fewer walls are available in an HDB kitchen for placing countertops. For this reason, a kitchen in an HDB flat should be ideally designed slightly larger than 9m2. Among the analyzed kitchen examples, no kitchen could be referred to as a “minimum small kitchen”. Those small kitchens analyzed were either too small or had unsuitable shape. In Chapter VI, two examples are offered as “Minimum small kitchen”. The dimensions of the kitchens and its appliances were designed according to the related guidelines (for details please see Chapter VI: Tests on Barrier-free Kitchen Examples, Section 6.1 & 6.2). Application: When the “Optimum small kitchen” was designed for test, its area was set around the 9m2. 5.3.2. Kitchen Shapes The kitchen’s shape plays an important role in the layout. There were 16 different shapes that had been identified among the kitchens from 1978 to 1999. All these shapes are illustrated in Table 5.7. The kitchen shapes could be further approximately classified into two groups – 57 regular and irregular shape. With the exception of s1 and s2 which are regular, the rest are irregular in shapes. Shape Sample Shape Sample s1 Regular Kitchen 9394-03 s2 Regular Kitchen 7980-08 s3 Irregular Kitchen 7778-01 s4 Irregular Kitchen 7980-07 s5 Irregular Kitchen 8182-07 s6 Irregular Kitchen 8182-08 s7 Irregular Kitchen 8182-10 s8 Irregular Kitchen 8182-11 s9 Irregular Kitchen 8182-12 s10 Irregular Kitchen 8283-07 s11 Irregular Kitchen 8788-04 s12 Irregular Kitchen 8283-09 s13 Irregular Kitchen 8586-01 s14 Irregular Kitchen 8384-02 s15 Irregular Kitchen 8485-02 s16 Irregular Kitchen 8788-01 Table 5. 7: Shapes of HDB kitchens from 1978 to 1999. One indicator about the shape is the location of the doors. The number of doors and their locations influence the usage of the kitchen obviously. With different door arrangements, the 58 layout of the kitchen varies greatly. With the same areas, kitchens in different shapes may have different layouts, and thus have different accessibilities. An improper shape may cause bad layouts and functions of a kitchen. 5.3.2.1. Kitchen analyses Analyses of some kitchens which were too narrow (e.g. Kitchen 9798-01) showed that though their areas were big, they were still a source of constraint for wheelchair users. For a kitchen with an irregular shape, the utilization of the space could be ineffective (e.g. Kitchens 8687-02, layout 1, 8586-01; 8182-07, layout 1). For details please see Appendix 21: Examples of Schematic Analysis about Kitchen Shape. Generally a rectangular shape, which is not too narrow, is preferred. For HDB kitchens, the doors are mostly towards a living room and a bathroom. They are better placed on one side of the kitchen and as close as possible so that the area used for traffic can be less. If doors are placed at diagonal corners, the traffic route will occupy more area and may also separate the working zones (Figure 5.14). Figure 5. 14: (Left) when doors are put close to one another, the traffic area is small; (Right) when doors are put at diagonal corners, the traffic area is large. Since there were few examples of every shape and they had different layouts and areas, it was hard to justify or evaluate the different shapes. There was no evaluating standard which could 59 fit for every shape. Therefore, quantitative analysis of the shapes was not conducted. However in future, further studies can be conducted to evaluate the different shapes for barrier-free kitchens. Application: Three rectangular shapes were applied to the tested kitchens for a qualitative study. Their widths were according to the estimated dimensions of the minimum width of the kitchen (for details please see Chapter VI, Sections 6.1 & 6.2). The doors of the tested kitchens were also designed close to one another in order that the traffic area could be small. 5.3.3. Place of Sink and Cooker The first consideration on the location of a sink and a cooker is to place them at a suitable place to create a convenient work triangle. In Singapore HDB flats, water and gas supply pipes are usually pre-installed in the kitchens. Once the pipes are located at a certain place in a kitchen, usually the places of sink and cooker are determined too. If the pipes are fixed in the wrong place, the unfitted sink and cooker location will cause bad working routes and low efficiency. Adaptation will then be troublesome too. The most important appliance perhaps is the sink. According to Donlan and Robinson (1978, p41), “Suffice it to say that it (sink) is probably the most important single piece of equipment in the kitchen. It is used more often, for more things, and in more ways than any other item in the kitchen. Thus, locating it in the best possible spot is vital to the whole kitchen plan.” The analysis about the kitchen plans showed that bad location of a sink can cause bad working layout (e.g. Kitchen 8788-01, layout 1). For details please see Appendix 22: Example of Schematic Analysis about the Bad Location of a Sink. 60 5.3.3.1. Cooking process and routes Another consideration of the cooker and sink is where to place them in relation to the refrigerator. Which should be located nearer to the refrigerator? Many kitchen design guidebooks recommend that the cooking process and layout should be from refrigerator to sink to cooker (Barrier Free Environments, Inc., 1991; Donlan & Robinson, 1978; Grandjean, 1973). For example, food is typically removed from the refrigerator, washed at the sink, and then cut and seasoned at a work counter. Next, it is put in a pan or wok for cooking. After serving and eating has ended, cleanup follows a similar pattern, with scraping and rinsing occurring before placing the dishes and utensils in the dishwasher. After being washed and dried, dishes and utensils are reinstalled in cupboards, cabinets, or drawers. This cooking process suggests that the sink should be nearer to the refrigerator. The method for testing the layouts and routes of HDB kitchens is based upon the method “Fadenstudie” (for details please see Appendix 23: Method for Route Testing). According to Conran (1977), tea making is usually used for testing routes. Because the recommended tea making test does not involve the refrigerator, a new procedure – instant noodle making – was used to test the HDB kitchen layouts in this thesis. The procedure for making instant noodles is: 1. Pick up a boiler from the cooker, take it to the sink and fill it with water; 2. Return it to the cooker and turn on the burner; 3. Pick up a vessel from the pan-cupboard, put it in the sink; 4. Get vegetables from the refrigerator, take them to the sink and wash them in the vessel; 5. Get the vessel with the washed vegetables to the counter and cut the vegetables; 6. Get the instant noodles from the cupboard to the counter; 7. Get the bowls from the pan-cupboard to the counter; 8. Get eggs from the refrigerator to the counter, then crack eggs into a bowl; 9. When the water in the boiler is boiling, put the noodles into the hot water; 10. Put in the vegetables, eggs and flavoring; 11. When the noodles are cooked, turn off the fire. 61 The lengths of routes for making instant noodles in each kitchen layout were measured. For each layout, there were two routes: (1) the route when the cooker was nearer to the refrigerator (NL1); and (2) the route when the sink was nearer to the refrigerator (NL2). Compared with the first route, the difference of the second route was that the sink and cooker were swapped. There is an assumption that the pans were placed near the sink and the noodles were stored near the refrigerator. Figure 5.15 exemplifies the two routes of a kitchen’s layout. Figure 5. 15: Two routes for instant noodle making in Kitchen 8182-11. 28 kitchens (whose area are smaller than 15m2) and 35 layouts were tested. The lengths of the two instant noodle making routes of each layout were measured. The results are shown in Figure 5.16 and Table 5.8. 62 Figure 5. 16: Lengths of the two routes in each kitchen layout. (NL1, the route length when cooker is nearer to refrigerator; NL2, the route length when sink is nearer to refrigerator.) No. 1 2 Kitchen k7778-01 k9596-01 NL1 (m) 16.61 13.03 NL2 (m) 16.64 11.42 No. 19 20 3 k9596-02 14.96 12.67 21 4 k8182-08 17.2 13.26 22 5 6 7 8 k9495-01 k9293-03 k9394-03 k9697-02 k8283-07, layout 1 k8283-07, layout 2 k7879-01, layout 1 k7879-01, layout 2 k9293-02, layout 1 k9293-02, layout 2 18.23 20.44 20.1 20.2 21.54 19.86 20.36 20.84 15.76 9 10 11 12 13 14 15 16 17 18 k9798-01 k7980-02, layout 1 k7980-02, layout 2 k8586-01 NL1 (m) 21.94 15.9 NL2 (m) 17.4 12.52 15.17 14.33 14.68 15.26 23 24 25 26 Kitchen k8384-02 k8485-02 k8182-07, layout 1 k8182-07, layout 2 k8485-05 k7980-08 k8182-10 k7980-03 21.95 19.16 20.17 21.95 17.17 18.13 18.67 19.62 12.84 27 k8182-11 16.63 14.97 22.1 19.07 28 23.8 22.16 15.94 16.5 29 21.96 21.48 16.88 14.33 30 k7980-04 21.84 17.22 16.29 16.26 31 k7980-07 18.97 17.15 14.72 14.06 32 20.69 19.35 27.71 24.01 33 18.21 16.55 19.57 18.37 34 k8384-04 21.96 21.14 20.04 17.4 35 k8687-02 23.34 22.99 17.94 16.95 k8788-01, layout 1 k8788-01, layout 2 k8788-04, layout 1 k8788-04, layout 2 Table 5. 8: Lengths of the two routes in each kitchen layout. 63 Comparison of the two routes of the 35 layouts shows that on most occasions, the route length of instant noodle making when the cooker is nearer to the refrigerator (NL1) is longer than the route length when the sink is nearer to the refrigerator (NL2). The average difference is about 1.53m. The largest difference is 4.78m. The longer route is time/effort consuming for a wheelchair user especially when the cooking is complicated and requires much transferring between working centers. If this phenomenon is true, when extended to other cooking processes, it means that the refrigerator should be placed nearer the sink rather than nearer the cooker. However, in many HDB kitchens the situation is just the opposite, especially for the one-sided kitchen where the refrigerator is placed near the entrance to the living room and the sink near the window. The cooker is often placed in the middle of the refrigerator and the sink. This sequence may cause a longer cooking route. When it is possible, the appliances should be designed from refrigerator to sink to cooker. Application: In the mock-up test kitchens, the layouts were designed from refrigerator to sink to cooker because this process was reasonable and recommended by most of the guidebooks. 5.3.3.2. Limitation The route analyses which were conducted only through a graphical study of the kitchen floor plans had a limitation. The routes of the wheelchair users may be too “ideal”. The length of the route measured between the cooker, sink and refrigerator were direct distances. But, in reality, the movements of a wheelchair user may not be so simple. Therefore, a practical study on the wheelchair users’ movements was conducted in the mock-up test kitchens. Because the mockup kitchens were not real kitchens and the subjects could not do real cooking, the whole route process could not be tested; only the most important steps of the routes were selected for the 64 tests. One route was from a door of the living room to a refrigerator, to a sink, and then to a cooker; the other route was from a sink to a microwave oven. 5.3.3.3. Place of Sink and Cooker Conventionally the kitchen sink is placed at a window. According to Koontz (1994), “placement of a window over the kitchen sink remains desirable simply in terms of visual relief from tasks and the aesthetic value of a connection to the outdoors” (Koontz, 1994). When it is impossible to place the sink under a window, the alternative is to put the sink close to openings so that a view is provided. According to Donlan & Robinson (1978), the cooker should not be placed too near a window or a door since wind from the window or door could put out the fire. Thus the cooker should be kept away from door (Figure 5.17). Furthermore, adequate counters should be provided on both sides of the cooker (for details please see Appendix 15: Minimum Width of the Different Kitchen Layouts, 3: L-shaped Kitchen). Figure 5. 17: A cooker should not be placed too near a window or a door (source: Donlan & Robinson, 1978). 65 Application: The following 5 principles were applied to design the mock-up test kitchens: (1) the sink is preferred to be near the window; (2) cooker should be kept away from the door and window; (3) the cooking process should be from refrigerator to sink to cooker; (4) adequate countertop should be provided on both sides of the sink and cooker; (5) adequate clear space should be provided at the sink and cooker. For details please see Chapter VI, Sections 6.1 & 6.2. 5.3.4. Place of Refrigerator The refrigerator should be placed near the service entrance so that it is convenient to transfer the purchased grocery (Koontz, 1994). Therefore, in a HDB flat, the suitable place for refrigerator is near the door to living room in the kitchen. 5.3.4.1. Refrigerator’s place related to the sink and cooker In HDB kitchens, there are three possible locations of the refrigerator related to the sink and cooker. The first location is at the end of a continual countertop in which the sink and cooker are installed together. The countertop can be L-shaped (e.g. Kitchen 7879-01, layout2) or “one wall” (e.g. Kitchen 7879-01, layout3). The second possible location of a refrigerator is with an appliance on a continual countertop and the other appliance on the opposite countertop (e.g. Kitchens 8485-02, layout 2; 7980-08, layout 1). The third possible location for a refrigerator is that the refrigerator is freestanding apart from the sink and the cooker (e.g. Kitchens 8586-01; 7980-08, layout 2; 8182-07, layout 2). For details about the example kitchens please see Appendix 24: Refrigerator’s Place Related to the Sink and Cooker. 5.3.4.2. Refrigerator’s door direction and landing space The direction of the refrigerator’s door impacts on the work triangle and traffic patterns. According to Koontz (1994), first, the latch side of the refrigerator rather than the hinge side 66 should be on the side of the work triangle. This arrangement avoids the trouble of carrying food around the refrigerator door to other work centers. Second, the refrigerator door should not block other cabinet or appliance doors when it is opened. Third, adequate space should be left so that the refrigerator door can be opened to an angle of at least 90 degree (Figure 5.18). Some refrigerators are now equipped with pull-out shelves. To facilitate the access to stored food in these drawers, the door has to be opened at a full 180 degrees (Barrier Free Environments, Inc., 1991). To make this possible, the refrigerator must not be located just adjacent to a wall or a partition or a cabinet. A distance is required larger than the refrigerator door. Figure 5. 18: Refrigerator placement considerations (Source: Donlan & Robinson, 1978). In order to facilitate taking items into and out of the refrigerator, a landing space is needed on the latch side of the refrigerator. The landing space is recommended to be at least 38cm (15”) wide (Peterson, 1998). Analysis of the HDB kitchen plans showed that in a constrained space, the refrigerator was often located at an unsuitable place. Inadequate space was provided for the door opening and the latch side was not on the work triangle (e.g. Kitchen 8182-08). Some kitchen examples showed that landing space could not be provided beside the refrigerator because of space 67 constraint (e.g. Kitchen 7980-08). For details please see Appendix 25: Example of Schematic Analysis about the Refrigerator Door and Landing Space. Application: To sum up, the refrigerator should be placed according to the following 5 principles: (1) it should be placed near the door to the living room in the kitchen; (2) the latch side of the refrigerator should be on the side of the work triangle; (3) suitable distance should be left on both side of the refrigerator for door opening; (4) landing space should be provided on the latch side of the refrigerator; (5) adequate clear space should be provided at the refrigerator. These principles were applied to design the mock-up test kitchens. For details please see Chapter VI, Sections 6.1 & 6.2. 5.3.5. Place of Washing Machine and Clothes Drying 5.3.5.1. Location of washing machine The location of a washing machine should not block the ways of the wheelchair user. Usually the washing machine is placed near the bathroom door for easy water access and drainage. When the washing machine is placed in front of the bathroom door, a clear floor space must be provided for a wheelchair user to approach the washing machine as well as the bathroom (e.g. Kitchens 9293-01; 7980-08; 8788-04). For details please see Appendix 26: Place of Washing Machine and Clothes Drying. 5.3.5.2. Clothes drying An adjustable device suspended from the ceiling for clothes drying is suitable for wheelchair users (for details please see the Chapter IV, Section 4.6: Clothes Washing and Drying). After hanging the clothes, the device can be raised again in order to free the space below. When the device is dropped down, it should be easy for a wheelchair user to transfer clothes from the 68 washing machine to the device (e.g. Kitchens 8182-07; 8485-05). For details please see Appendix 26: Place of Washing Machine and Clothes Drying. Application: To sum up, a washing machine should be placed according to the following principles: (1) the washing machines are better placed near the bathroom or adjacent to the water pipes; (2) when the washing machines is freestanding, it should not block the way for wheelchair users; (3) clear floor space should be provided at the washing machine. All these three principles were applied to design the mock-up test kitchens. For details please see Chapter VI, Sections 6.1 & 6.2. The location of the clothes drying should be according to following principles: (1) when the devices are lowed down, it should not block the ways of the wheelchair user; (2) transferring clothes from the washing machine to the device should be easy and in a short distance. Because the mock-up test kitchens were made of cardboard, drying clothes by using this kind of device was unable to be tested. Only the preferred locations of the clothes pole were asked to the subjects when the kitchens were tested. Table 5.9 is the summary of the observations, recommendations and applications on the aspects of the floor plan design. 69 Observations in the 5 kitchens (for the details please see Chapter III) Recommendations after schematic analyses Applications Approaching spaces at doors It was assumed that swing doors were used in the tested kitchens. The doors also swing outwards. The first three approaching spaces were applied to the mock-up test kitchens. (1) front approaches to a swinging door (push side, according to Singapore Guidelines) (2) hinge-side approaches to a swinging door (according to the test result) (3) latch-side approaches to a swinging door (push side, according to NKBA Guidelines) (5) sliding-side approaches to a sliding/folding door (according to NKBA Guidelines) (6) latch-side approaches to a sliding/folding door (according to NKBA Guidelines) In the five kitchens, no door was used at the entrance towards the living room. In the two modified kitchens the wall between the living room and kitchen were removed. (4) front approaches to a sliding/folding door (according to NKBA Guidelines) Turning space for wheelchair users The large turning space was applied to design the “Optimum small kitchens”. The tests at HWA showed that in the large turning space, the subjects turned easily and took less time than that in small turning space or T-shaped turning space. The small turning space was applied to design the “Minimum small kitchens”. Large turning space (1800mm, according to Singapore Guidelines). The tests at HWA showed that in the small turning space, the subjects turned difficultly and took more time than that in large turning space. Kitchen No. 2 had the narrowest space. The width was 2.35m. The clear space for wheelchair to turn was 1.75m. Its owner could turn well inside. In the other four kitchens the wheelchair users could turn easily. Small turning space (1520mm, according to NKBA Guidelines) 70 Observations in the 5 kitchens (for the details please see Chapter III) Minimum with of the different kitchen layouts Recommendations after schematic analyses Applications One-sided Kitchen No problems were found about the widths of the five kitchens. 240cm (According to Singapore Guidelines) 212cm (According to NKBA Guidelines) 192cm (According to Singapore Guidelines) 164cm (According to NKBA Guidelines) L-shaped Kitchen When a sink is placed on the leg of the “L” 240cm (According to Singapore Guidelines) 212cm (According to NKBA Guidelines) 194cm (According to Singapore Guidelines) 194cm (According to NKBA Guidelines) 240cm (According to Singapore Guidelines) 212cm (According to NKBA Guidelines) 192cm (According to Singapore Guidelines) 181cm (According to NKBA Guidelines) The minimum widths for L-shaped and U-shaped kitchen were applied to design the mock-up test kitchens for qualitative studies. Kitchen No. 1 was a two sided kitchen; the width is 3.39m. Kitchens No. 2 and No. 3 were L-shaped kitchens; the widths were 2.34m and 3.6m respectively. Two-sided Kitchen / U-shaped Kitchen 300cm (According to Singapore Guidelines) 272cm (According to NKBA Guidelines) When a cooker is placed on the leg of the “L” Kitchens No. 4 and No. 5 were one-sided kitchens; The widths were 2.47m and 2.73m respectively. 252cm (According to Singapore Guidelines) Minimum width of a wall with doors 224cm (According to NKBA Guidelines) The layouts (2), (3) and (10) were applied to design the mock-up test kitchens for qualitative studies. No problem was found in the five kitchens. ⑴ a swing door ⑹ two countertops + a large turning space (part of which is under a countertop) ⑵ a swing door + a countertop ⑶ a countertop + a small turning space ⑺ two countertops + a small turning space (no part of which is under a countertop) ⑻ two countertops + a large turning space (no part of ⑷ a countertop + a large turning space ⑼ two swing doors + a countertop ⑸ a swing door + two countertops, with a small turning space (part of which is under a countertop) ⑽ two swing doors + two countertops 71 Observations in the 5 kitchens (for the details please see Chapter III) Clear Floor Space for a Wheelchair User at Appliances Basic Area Requirement Kitchen Shapes No problem was found in the five kitchens. One kitchen was 7.53m2 before the modification. It showed that the area was too small for its owner. There was no problem about the area of the four other kitchens whose area were larger than 10m2. All kitchens were in rectangular shapes Recommendations after schematic analyses Applications Singapore Guidelines Clear floor space 90cm×120cm NKBA Guidelines ADA Guidelines 76cm×122cm 76cm×122cm which is under a countertop) Sitting direction Parallel approach and perpendicular (forward ) approach Same as above Same as above The area of an “Optimum small kitchen” seemed to be around 9m2 for a wheelchair user to perform basic kitchen tasks. A rectangular shape, which is not too narrow, is preferred. Place of Sink and Cooker Cooking process and routes Place of sink and cooker Clear floor space under work surface 48cm deep The clear floor space requirements were applied to design the mock-up test kitchens. 48cm deep 48cm deep When the “Optimum small kitchen” was designed for test, its area was set around the 9m2. Three rectangular shapes were applied to design the mock-up test kitchens for qualitative studies. Their widths were according to the estimated dimensions of the minimum width of the kitchen. In the mock-up test kitchens, the layouts were designed from refrigerator to sink to cooker. In 3 kitchens the layouts were from the refrigerator to cooker to sink. The reasonable layout is from a refrigerator to a sink to a cooker. The sinks in 4 kitchens were near the window. The cookers in all the 5 kitchens were far away from the window. (1) The sink is preferred to be near the window; (2) Cooker should be kept away from the door and window; (3) The cooking process should be from refrigerator to sink to cooker; (4) Adequate countertop should be provided on both sides of the sink and cooker; (5) Adequate clear space should be provided at the sink and cooker. (1) It should be placed near the door to the living room in the kitchen; (2) The latch side of the refrigerator should be on the side of the work triangle; (3) Suitable distance should be left on both side of the refrigerator for door opening; (4) Landing space should be provided on the latch side of the refrigerator; (5) Adequate clear space should be provided at the refrigerator. All these five principles were applied to design the mock-up test kitchens. For the washing machine: (1) The washing machines are better placed near the bathroom or adjacent to the water pipes; (2) When the washing machines is freestanding, it should not block the way for wheelchair users; (3) Clear floor space should be provided at the washing machine. The three principles for the washing machine were applied to design the mock-up test kitchens. Place of Refrigerator All these five principles were applied to design the mock-up test kitchens. In two kitchens the refrigerators were placed at the corner near the entrance. They were hard to use. In two kitchens the refrigerators’ latch sides were not on the work triangle. Place of Washing Machine and Clothes Drying For the clothes drying: (1) When the devices are lowed down, it should not block the ways of the wheelchair user; (2) The transferring clothes from the washing machine to the device should be easy and in a short distance. Because the mock-up test kitchens were made of cardboard, drying clothes by using this kind of device was unable to be tested. Only the preferred locations of the clothes pole were asked to the subjects when the kitchens were tested All the washing machines in the five kitchens were inaccessible. Table 5. 9: Summary of the observations, recommendations and applications. 72 CHAPTER VI. TESTS ON BARRIER-FREE KITCHEN DESIGNS In the last two chapters, the main existing barriers in HDB kitchens were analyzed in both vertical and floor plan designs. Some recommendations were then given for a more accessible kitchen design. However, all these analyses were only through literature and separated from each other. In this chapter, the author tried to combine these analyses by offering some barrier-free kitchen designs. In the three designs, doors were positioned close to each other so that the traffic area could be the smallest. Three kitchens were designed and tested. One kitchen was designed as an “Optimum small kitchen”, which provides large appliances, more storage and large turning space. The other two kitchens were designed as “Minimum small kitchens” which provide small appliances, less storage and smaller turning space. 6.1. The Optimum Small Kitchen Designed for Test 6.1.1. Floor Plan Design of the Optimum Small Kitchen Figure 6.1 shows the floor design of an “Optimum small kitchen”. The dimensions of the kitchen were determined by both the requirements of the appliances and the requirements of wheelchair users. It was assumed that large cooker (700mm in length) and sink (800mm in length) were installed in an optimum kitchen. A large turning space of 1800mm (according to Singapore Guidelines) was catered for. The width of the kitchen was determined by the depth of the countertop (600mm) and the tuning space of a wheelchair user (1800mm). The width was 2400mm. The length of the 73 kitchen was mainly decided by the two countertops (600mm×2) and the approaching space to the two doors (1200mm×2). The whole length was 3600mm. The work centers were arranged following the sequence: refrigerator to sink to cooker. Two doors were put adjacent to one wall. Thus a U-shaped kitchen was formed. The kitchen area was 8.64m2. Figure 6. 1: Plan of the “Optimum small kitchen” (unit: mm). (R – refrigerator; RS – rotating cabinet; MW – microwave oven; WM – washing machine; S – sink; C – cooker; D – drawers). Some details are explained below according to the numbers assigned in the Figure 6.1. 74 ⑴ The refrigerator was 600mm in length and 600mm in depth (according to the commonly used refrigerator’s dimensions). The distance between the refrigerator and the wall was 600mm; thus the refrigerator door could be opened at 180o (according to Barrier Free Environments, Inc., (1991)). ⑵ A pull-out countertop served as the landing space for the refrigerator (according to Peterson, (1998)). ⑶ A rotating corner cabinet (also called “Corner Lazy Susan”) could increase access to the interior of the cupboard at the corner (according to Barrier Free Environments, Inc., (1991)). ⑷ The Microwave oven was 500mm in length and 400 in depth (according to the commonly used microwave oven’s dimensions). ⑸ The washing machine was placed under the counter. It was a front-loaded model, 600mm in length and 600mm in depth (according to the commonly used washing machine’s dimensions). ⑹ A pull-out countertop in front of the microwave oven could serve as a landing space for pans (According to the NKBA guidelines). ⑺ The sink was 800mm in length. According to the NKBA guidelines, there should be clear countertops more than 460mm on one side and 610mm on the other side. In this kitchen plan, adequate clear countertops were provided on both sides of the sink. The distance between the sink and the Microwave oven was 470mm (>460mm); the distance between the sink and the countertop edge was 130mm and the distance between the cooker and the countertop edge was 720mm. The total was 850mm (>610mm). A clear knee space was provided under the sink. ⑻ A pull-out countertop was set between the cooker and sink (according to Barrier Free Environments, Inc., (1991)). ⑼ The cooker was 700mm in length. Adequate clear countertops were provided on both sides of the cooker (more than 380mm on one side and 230mm on the other side) (according to NKBA Guidelines). The same as the sink, a knee space was provided under the cooker. ⑽ Beside drawers a knee space was provided. 75 ⑾ A clear floor space of 900mm×1200mm was provided at the refrigerator (according to Singapore Guidelines). ⑿ A clear floor space of 900mm×1200mm was provided at the sink (according to Singapore Guidelines). ⒀ A clear floor space of 900mm×1200mm was provided at the cooker (according to Singapore Guidelines). ⒁ An approaching space of 1200mm×1200mm was provided at the living room door; beside the latch side of the door, 300mm is provided (according to Singapore Guidelines). ⒂ An approaching space of 1200mm×1200mm was provided at the bathroom door (according to Singapore Guidelines). ⒃ A turning space of 1800mm×1800mm was provided without any part under the countertop (according to Singapore Guidelines). 6.1.2. Vertical Design of the Optimum Small Kitchen Based on the anthropometric study of the wheelchair users’ reach, heights were set for the appliances, countertop, cabinet doors, drawer handles and switches/outlets, etc. According to the reach study results, the comfortable reach range to a wall of the wheelchair users is from the height 420mm to 1100mm. Therefore, most of the appliances and the storage were set in this range. The maximum reach range to a wall of the wheelchair users is from the height 350mm to 1200mm. Therefore, the lowest drawers’ handles were set in this range. The maximum upward reach of the wheelchair user is 1350mm thus the height for the ventilation hood was set less than 1350mm. The bottom of the wall storage was set at a comfortable reach height of 1060mm (for details please see Chapter IV, Section 4.4.8: Summary of the Reach). Figure 6.2 is the A-A section design of the “Optimum small kitchen”. Figure 6.3 is the B-B section design. In the two sections, the countertop height was set at 800mm. 76 Figure 6. 2: A-A section of the “Optimum small kitchen” (unit: mm). (MRR – maximum reach range; CRR – comfortable reach range; WC – wall cabinet; RS – rotating cabinet; AS – accessible switches; MW – microwave oven; WM – washing machine; VH – ventilation hood; HS – hood switches). Figure 6. 3: B-B section of the “Optimum small kitchen” (unit: mm). (MRR – maximum reach range; CRR – comfortable reach range; VH – ventilation hood; HS – hood switches). The details are explained below according to the numbers assigned in Figure 6.2: ⑴ The height of the countertop was 800mm. ⑵ The bottom of the counter was 650mm. ⑶ Two small pull-out countertops were provided between the sink and the cooker. 77 ⑷ The thickness of the sink was 150mm. A long lever sink handle was used for a wheelchair user to operate. A clear knee space was provided under the sink. The drain was located at the rear of the sink bowl to provide more room for the knee. Pipes below the sink were covered by a removable sloping board to protect wheelchair users from inadvertent contact with the pipes. The sink faucet was with a long lever handle for easy operation by wheelchair users. ⑸ The thickness of the cooker was less than 150mm. The controls should be front-mounted. ⑹ The bottom of the wall cabinet should be less than the height of 1060mm (according to the measurement results of the reaches). ⑺ The drawers beside the sink could store small kitchen utensils. ⑻ The washing machine was smaller than the usual model so that it could be placed under the counter. The opening was in the reach range of the wheelchair user. ⑼ The handles attached to the lowest drawers were in the maximum reach range of the wheelchair users (higher than 350mm from the floor, according to the measurement results of the reaches). The handles were D-shaped to make it easy to use. ⑽ Accessible switches/outlets could be installed in an accessible drawer. ⑾ The hood switch was in the maximum reach range of a wheelchair user ([...]... primary barriers for wheelchair users in HDB kitchens The barriers were classified into two categories: vertical design and floor plan design Vertical design Step 2: Vertical design Survey about the operations and appliances in HDB kitchens for wheelchair users Field investigation of five kitchens Reaches Literature review Recommendations in Singapore Guidelines Anthropometric measurements on 32 wheelchair. .. Code on Barrier- free Accessibility in Building, 2002 (Building and Construction Authority, 2002) But in this code, only a little information is available about the kitchen design for wheelchair users 11 CHAPTER III IDENTIFYING THE PRIMARY BARRIERS FOR WHEELCHAIR USERS IN HDB KITCHENS 3.1 Selection of Kitchens Used by Wheelchair Users Field investigations were conducted in order to acquire more information... of other rooms also influences a kitchen s floor shape Some HDB kitchens were built in irregular shapes (HDB, 1977-1999) For these reasons, a wheelchair user who lives in an HDB flat may face some barriers in the kitchen 2 This research focused on the understanding of the primary barriers for wheelchair users in small HDB kitchens, how the barriers arise and how they can be solved/avoided The findings... too high for the wheelchair users to take the washed clothes out of the washing machines Therefore, the wheelchair users did not use them Most Singapore residents in HDB flats use bamboo poles to hang wet clothes out through the window for drying However, it was impossible for the 5 wheelchair users to do so The clothes hanging devices inside the kitchens were also too high for the wheelchair users to... Other rooms linking to the kitchen were not discussed 7 1.4.3 Scope of the Operations and Appliances in HDB Kitchens for Wheelchair Users Many operations can be conducted in a kitchen There are also varied appliances used in a kitchen In order to identify the important operations and appliances accommodated in HDB kitchens for wheelchair users, a survey was conducted at HWA (for details please see Appendix... applied to the floor plan design of the mock-up test kitchens The third step of the research methodology was to test the barrier- free kitchens newly designed After the general analyses of the existing kitchen plans, three barrier- free kitchens were designed Then the second method was used to test the kitchen examples Mock-ups were built in true scale at HWA 12 wheelchair users took part in the experiment... between wheelchair users and the kitchen Such an understanding can then help in the creation of supportive home spaces for wheelchair users in future 1.2 Research Objectives The objectives of this research are mainly three: 1) To identify the primary barriers (on the physical aspect) for wheelchair users in small HDB kitchens 2) To understand the current situations of and reasons for these barriers... were applied to the vertical design of the mock-up test kitchens With regard to floor plan design, the main discussions were about the rational area and layouts of the HDB kitchens from the viewpoint of the barrier- free design for wheelchair users There were three possible methods of carrying out the kitchen floor plan analysis The first was to utilize floor plan drawings for floor plan analysis The... applications 72 Table 6 1: The wheelchair users selected for the test 88 Table 6 2: Scenario test results in the seven kitchens 146 Table 6 3: Different approaching methods for different wheelchair users 150 Table 6 4: Different approaching methods for different wheelchair users 152 Table 6 5: Different approaching methods for different wheelchair users 154 Table 6 6: Routes... investigations provided more specific information about the present, local conditions of the kitchens used by wheelchair users in Singapore HDB flats They were necessary for identifying the primary barriers for wheelchair users in the local context After the barriers had been identified, the barriers were classified into two groups: one group was related to vertical design and user’s reach (such as the ... BARRIERS FOR WHEELCHAIR USERS IN HDB KITCHENS 3.1 Selection of Kitchens Used by Wheelchair Users Field investigations were conducted in order to acquire more information about the local HDB kitchens... barriers (on the physical aspect) for wheelchair users in small HDB kitchens 2) To understand the current situations of and reasons for these barriers 3) To give recommendations for barrier- free. .. the primary barriers for wheelchair users in HDB kitchens The barriers were classified into two categories: vertical design and floor plan design Vertical design Step 2: Vertical design Survey