One of the most important design considerations that residential architects have the responsibility to address is accessibility, ensuring that people with disabilities can comfortably live at home without impediments blocking basic home functionality. Accessibility for wheelchair users is a particularly important architectural concern due to unalterable spatial, material, and other requirements necessitated by wheelchair design and use. Because guaranteeing the comfort of all users, including disabled users, is one of the most essential obligations of all architects, designing for wheelchair users must be done with utmost the attention and care, especially in residential environments. Below, we delineate several strategies for designing floors for wheelchair circulation, helping architects achieve this goal of maximum comfort and accessibility.
Residential floors that successfully accommodate for wheelchair users above all provide ample space for moving, rotating, and accessing appliances and surfaces. Thus, corridor width and turning radius requirements continually reappear in almost every aspect of accessible residential design. These open corridors and clear floor spaces are as flat as possible and have as few obstacles as possible, with few sudden grade changes and smooth transitions between different areas. Finally, floors that favor wheelchair circulation are also made of non-slip materials friendly to extended wheelchair use.
Accessible Routes & Turning Space
According to the 2010 ADA Standards, each residential dwelling unit must contain at least one accessible route connecting all spaces and elements to ensure that wheelchair users can access all functions of the apartment or home. Such routes may include low-slope walking surfaces, ramps, elevators, or platform lifts. Each of these routes also require certain minimum dimensions to facilitate wheelchair accessible circulation. Accessible walking surfaces, likely the most common accessible route to be used in any residential dwelling, must be 36 inches wide minimum, have a running slope no greater than 1:20, and have a cross slope no greater than 1:48. As we stated in an earlier article, although 36 inches is the minimum, a corridor width of 150 cm or 60 inches will most comfortably accommodate all accessibility needs. Of course, these corridors must also be clear of obstacles or other forms of interruption.
For residential dwellings with multiple floors, stairs are obviously not accessible to wheelchair users. Instead, architects can incorporate ramps, elevators, or platform lifts to meet ADA guidelines. Like walking surfaces, the width of a ramp must be a minimum of 36 inches, and the cross slope may not exceed 1:48. However, the maximum running slope is 1:12, not 1:20. Furthermore, elevator car dimensions must be a minimum of 42 inches wide and 54 inches deep, while platform lifts must be a minimum of 30 inches by 48 inches. For more specific details on each of these options, architects should consult the ADA guidelines themselves.
Alongside wide corridors, low slopes and cross slopes, and wheelchair accessible installments for access to different floors, accessible routes must also incorporate wide enough turning radiuses for wheelchair users to use. For routes that make a 180 degree turn around a wall or an object, the corridor must be 42 inches wide minimum while the turning area must be 48 inches wide minimum, or, if the corridor is only 36 inches wide, the turning area must be 60 inches wide minimum. For areas that require less than a 180 degree turn and use instead a circular or T-shaped turning space, the diameter or the width must be a minimum of 60 inches, as illustrated in detail in the 2010 ADA Standards Chapter 3.
In summary, residential dwellings with proper wheelchair circulation incorporate at least one continuous accessible route reaching every area of the unit that may include wheelchair specific turning spaces or multilevel elements.
Each of the spaces accessible by such routes must similarly be designed with ample space for wheelchair users to inhabit them comfortably. Architects can design accessible bedrooms through a series of relatively simple steps. All turning areas, as stated above, must leave at least 60 inches of space, such as around bed corners, desks, or drawers. Again, all corridors of space must be at least 36 inches wide as well. Of course, it is worth noting that floor circulation is not the only consideration for architects aiming to design accessibly. Altogether, the circulation of individual rooms will follow the larger guidelines listed above, but room-specific furniture items must often be altered further as well. In the bedroom, for example, closets and drawers should be designed to accommodate wheelchair users’ height and reach. Closets designed specifically for wheelchair users will have clothes rods lower to the ground, often around 30 inches high.
Designing exceptional kitchens is a difficult task even without considering accessibility – cooking patterns are often highly elaborate and rely heavily on quick circulation between different appliances. The appliances and kitchen workspaces themselves often have specific requirements that must be altered further to accommodate wheelchair users. The first and most obvious step to designing accessible kitchens is again to adjust for wheelchair clearance. For kitchens where counters or cabinets are on opposing sides – “pass through kitchens” – the space between these two sides must be a minimum of 40 inches. However, for U-shaped kitchens with three enclosing sides, clearance must be 60 inches minimum.
Moreover, mobility when interacting with specific work surfaces or appliances requires close attention as well. Before all kitchen work surfaces and appliances, architects must include a clear floor space allowing for a forward approach by a wheelchair user. This entails leaving a minimum of 30 inches by 48 inches of clear floor space in front of the surface or appliance. Furthermore, this clear floor space must adjoin an accessible route or another clear floor or ground space to allow access. The methods of measuring such spaces are highly specific and may or may not include the space underneath a cabinet or appliance if it is elevated above the ground. If architects choose to include that space, they must address toe clearance and knee clearance guidelines as well. These spaces require their own sets of dimensions to qualify as part of the clear floor space, and these sections of the ADA Standards should be studied in detail by architects. More requirements for specific appliances, such as dishwashers, cooktops, ovens, and refrigerators, are also listed in this section.
As with the bedroom, kitchen furniture for wheelchair users must also satisfy certain height and reach requirements. Kitchen work surfaces, for example, must be a maximum of 34 inches above the ground.
Toilet & Bathing Facilities
Like kitchens, toilets and bathrooms are another facet of residential dwellings that necessitate specific mobility and circulation requirements. For general circulation, the turning diameter of spaces must again be 60 inches minimum while corridors of space must be at least 36 inches wide. Moreover, each fixture, again like in kitchens, must have clear floor space in front of them. Sinks, for example, necessitate the same dimensions for clear floor space for a forward approach. Accessible bathtubs require a minimum of 30 inches clearance extending the length of the bathtub. Toilets require a clearance of 60 inches minimum from the side wall and 56 inches from the rear wall. Moreover, all wheelchair accessible bathroom fixtures, such as showers, bathtubs, toilets, and sinks, must be included in one wheelchair accessible bathroom – so that wheelchair users do not have to travel to different bathrooms to access each fixture.
For more specific recommendations on how to design bathroom fixtures themselves – especially showers and toilets, which have lengthy seating and grab bar requirements – readers should again consult the ADA guidelines themselves.
All accessible routes and rooms must have floors that are stable, firm, and slip resistant, as delineated in Chapter 3 of the 2010 ADA Standards. Although it may seem less obvious that floor materials are an essential part of accessibility, slippery or otherwise undesirable floors can serious harm users or damage the wheelchairs themselves. Stable, firm, and slip resistant floors are not damaged by force, such as the weight of the wheelchair; resist deformation; and have enough friction that they can be used safely. The best floor materials to these ends are solid or engineered hardwood floors, vinyl plank floors, or tile floors. Hardwood floors are easy to maintain and can be refinished if scuffed by the wheelchair. Additionally, hand-scraped or distressed finishes for hardwood floors can increase the friction coefficient of the surface and prevent slippage. Vinyl floors are less expensive but similarly slip resistant, although they cannot be resurfaced or refinished if damaged. However, they are easily and cheaply replaced. Finally, tile floors are extremely durable, and textured, non-skid tile is both slip resistant and firm. The ideal tile size to prevent damage is 2 inches square.
The worst materials for wheelchair users are heavily cushioned floors, which are extremely difficult to maneuver on if not designed for accessibility. A common example is carpet, which though soft and comfortable, can significantly increase the amount of force needed to move a wheelchair over the surface. Thus, architects should reserve carpet flooring for areas with the least amount of traffic, and when doing so, the carpet pile height still must not exceed ½ inch. Moreover, the carpet must be extremely securely attached, with exposed carpet edges fastened to floor surfaces and containing trim along the entire length of the exposed edges.