The site surrounding the facility should be surveyed during the review for handicapped accessibility and pedestrian and vehicular circulation, and layout should be reviewed for unimpeded access to the entrance of the facility. Likewise, the accessibility of the parking area, including the adequacy of location, dimensions, and identification of parking stalls, should be reviewed and recorded. Walkways should provide adequate access between various site areas and the building. These walkways should not be less than 48 inches wide and should not have a slope in excess of 5 percent (1 foot, 0 inches rise in 20 feet, 0 inches).
Accessibility is achieved by addressing the requirements of the ADA and other applicable codes as well as state and local regulations. There are essentially three accessibility documents that designers and consultants most frequently use and should be familiar with:
• ANSI A117.1 was developed by the American National Standard Institute (ANSI) and is one of the first accessibility guidelines to be used in the United States. The latest edition of ANSI A117.1/ICC is the 1998 edition, which was developed jointly with the International Code Council and the Access Board. This edition has been modified to be more in step with the ADAAG.
• The Americans with Disabilities Act Accessibility Guidelines (ADAAG) was developed by the Architectural and Transportation Barriers Compliance Board (ATBCB or Access Board) as a guideline for ADA legislation. It was based on the 1986 ANSI A117.1, but after the incorporation of additional requirements it became stricter than ANSI. The Access Board is responsible for making revisions to the ADAAG and is currently working with the DOJ on updating the ADAAG.
• The Uniform Federal Accessibility Standards (UFAS) are based on the 1980 ANSI standard and applies mostly to government buildings and organizations that accept federal funding. These buildings are not currently required to conform to ADA regulations.
The ADA stipulates that new construction and alterations to existing facilities comply with the ADAAG. For example, a new tenant space within an existing building is now considered by the ADA to be new construction and must comply with the ADAAG. Rules of compliance for alterations and renovations to existing buildings are sometimes complex, and under Title III of the ADA altered buildings must be made accessible if that is readily achievable. When prevailing conditions prevent barrier removal, a public accommodation has to make its services available through alternative means, such as relocating activities to accessible locations.
The ADAAG defines an accessible route as, "a continuous, unobstructed path connecting all accessible elements and spaces in a building or facility." This includes pathways, corridors, doorways, floors, ramps, elevators, and clear floor space at fixtures. Designing safe and barrier-free accessible routes is essential for people with disabilities, and enhancing their movement is critical to their wellbeing.
Adequate corridor width is essential to passage for someone with mobility or vision impairment. The ADAAG puts great emphasis on the provisions for access and egress and clearly delineates the requirements for length, space, lighting, signage, and safety measures. Corridors, for example, should ideally be a minimum of 42 inches (1065 mm) wide and not more than 75 feet (22.9 m) long. They should be well lit with indirect lighting to prevent glare. Wall finishes should incorporate blends of contrasting colors to increase visual acuity. Openings that form part of an accessible route should not be less than 32
inches (815 mm) wide. The minimum passage width for two wheelchairs is 60 inches (1525 mm). If an accessible route is less than 60 inches (1525 mm) wide, passing spaces at least 60 inches by 60 inches must be provided at intervals not to exceed 200 feet (61 m).
The ADAAG stipulates that the minimum clear floor space required to accommodate one stationary wheelchair is 30 inches (762 mm) by 48 inches (1220 mm). For maneuverability, a minimum 60-inch (1525-mm)-diameter circle is required for a wheelchair to make one 180-degree turn. In place of this, a T-shaped space may be provided.
Doors should have a clear opening width of between 32 (815 mm) and 36 inches (915 mm) when the door is opened at 90 degrees (Figure 11.8). The maximum depth of a 32-inch-wide (815-mm) doorway is 24 inches (610 mm). If the depth exceeds this, the width must be increased to 36 inches (915 mm). Threshold heights should not exceed 1/2 inch (12.7 mm) and should not contain any sharp slopes or abrupt changes but should be beveled so no slope of the threshold is greater than 1:2. Door closers should not hamper a door's use by the disabled. No part of an accessible route may have a slope more than 1:20 (1 inch rise for every 20 inches/508 mm distance). If a slope is greater than this, it is classified as a ramp and must meet different requirements including the handrail provision.
Barrier-free codes also require that door hardware meet certain specifications. Lever handles on doors for disabled people are usually cost-effective. All hardware on doors, cabinets, and windows should be easy to grasp and operate with one hand and should not need a tight grip for turning. This includes lever-operated, push-type mechanisms, and U-shaped handles. Standard doorknobs are not allowed.
If a toilet-stall approach is from the latch side of the stall door, clearance between the door side of the stall and any obstruction may be reduced to a minimum of 42 inches (1065 mm). Many toilet stalls are positioned at the end of a path of travel between the row of stalls and the wall (Figure 11.9). The advantage of using an end toilet for the accessible stall is that the grab bars can be fixed to the wall rather than to a partition, which allows sturdier anchoring to meet minimum strength requirements.
There are several toilet-stall layouts that meet ADA requirements. Toilet rooms as well as toilet stalls must have a minimum 60-inch (1525-mm) clear internal turning space. However, the clear floor space at fixtures and controls may extend up to 19 inches (483 mm) under a wall-mounted sink. The clearance depth varies depending on whether a wall-hung or floor-mounted water closet (60-inch by 56-inch minimum inside dimensions) is used. In most cases, the door must provide a minimum clear opening of 32 inches (815 mm) and must swing out, away from the stall enclosure. If a stall is less than 60 inches (1525 mm) deep, a 9-inch (225-mm) toe clearance is required under partitions. In planning toilet rooms, a 5-foot diameter (1525-mm) clear space should be allowed for.
Grab bars must also be provided as shown in Figure 11.10, mounted from 33 inches (838 mm) to 36 inches (915 mm) above the finished floor. Grab bars should be a minimum of 42 inches (1065 mm) long at a side wall and 36 inches (915 mm) at a rear wall. They should have a diameter of 1.5 inches (38 mm) and be located not more than 1.5 inches (38 mm) from the wall. In many toilets there is a lateral space to the side of the water closet, which only allows provision of a side horizontal rail. Toilet-paper dispensers are to be located below the grab bar, a minimum of 19 inches (483) above the finished floor.
In the absence of toilet stalls, the centerline of the toilet must still be 18 inches (455 mm) from a wall with back and side grab bars. A clear space should be provided in front of and to the side of open water closets.
Where urinals are installed, stall or wall-mounted urinals must be used with an elongated rim no more than 17 inches (430 mm) above the floor. A clear floor space of 30 inches (762 mm) by 48 inches (1220 mm) must be provided in front of the urinal. This space may adjoin or overlap an accessible route.
Public lavatories must allow wheelchair users to move under the sink and easily use the basin and water controls. Any exposed piping below the lavatory must be insulated or otherwise protected. ADAAG makes a distinction between lavatories, which are basins for hand washing, and sinks, which are other
types of basins. Faucets must be easy to operate with one hand without tight grasping or twisting of the wrist. Lever-operated, push-type, and automatically controlled mechanisms are acceptable.
Private residences are not typically subject to Title III of the ADA requirements; nevertheless, consultants should familiarize themselves with such requirements so as to be able to serve their clients better. In Figure 11.10 A we see a typical ADA-compliant residential bathroom in a senior living complex. Figure 11.10 B illustrates a prefabricated shower unit with strong grab bars in the shower, installed at different heights, along with a hand-held showerhead. These reflect some of the essentials of the accessible bathroom in the home.
Drinking water should be accessible with up-front spouts and controls that can be either hand- or floor-operated. Where only one drinking fountain is provided per floor, it should be accessible to people using wheelchairs, as well as persons who have difficulty bending or stooping. This can be resolved by the use of a "high-low" fountain, whereby one fountain is at a low level and accessible to those using wheelchairs and another is at the standard height for those who have difficulty bending.
Ramps should be installed as needed in areas of pedestrian-access level changes. They are required to provide a smooth transition between changes in elevation for both wheelchair-bound persons as well
as those whose mobility is otherwise restricted. In general, designers should use the least possible slope, but in no case should a ramp have a slope greater than 1:12 (1 inch in rise for every 12 inches in run). The maximum rise for any ramp is typically limited to 30 inches (762 mm), after which a level landing is required. A slope of up to 1:8 is permitted if the maximum rise does not exceed 3 inches (76 mm). In all cases a nonskid surface should be in place to enable traction in inclement weather.
A ramp's clear width must not be less than 36 inches, with landings that are at least as wide as the widest segment of the ramp leading to them. Landing lengths must not be less than 60 inches (1525 mm), and, if ramps change direction at a landing, the landing must be at least 60 inches square.
Handrails on both sides of ramps are to be incorporated if the ramps have a rise greater than 6 inches (152 mm) or a length exceeding 72 inches (1825 mm). The top of the handrail should be from 34 (864 mm) to 38 inches ((965 mm) above the ramp surface. Handrails must extend at least 12 inches (305 mm) beyond the top and bottom of the ramp segment and have a diameter or width of gripping surface from 1 1/2 (32 mm) to 1 1/2 inches (38 mm) for both ramps and stairs. Notice that the new ADAAG handrail guidelines are more flexible than the current guidelines (Figure 11.11).
The stairways should provide accessibility between building floors; when these stairs are not connected by an elevator, they must be designed according to certain standards specifying the configuration of treads, risers, nosings, and handrails. The maximum riser height is 7 inches (178 mm), and the treads must be a minimum of 11 inches (280 mm) as measured from riser to riser. Open risers are not permitted. The undersides of the nosings must not be abrupt and must conform to one of the styles shown in Figure 11.12. Stairway users are more likely to stumble or fall while going down stairs than when going up. Tread depth is pivotal in stair design. Typically when climbing a stairs, users place only part of their foot on the tread, whereas when descending the whole foot or most of the foot is placed on the tread.
Stairway handrails must be continuous on both sides of the stairs. The inside handrail on switchback or dogleg stairs must always be continuous as it changes direction. Other handrails must extend beyond the top and bottom riser. A handrail's top gripping surface must be between 34 (864 mm) and 38 inches (965 mm) above stair nosings. In addition, the handrail must have a diameter or width of gripping surface of between 1 1/4 inches (32 mm) and 1 1/2 inches (38 mm). There must also be a clear space between the handrail and the wall of at least 1 1/2 inches (38 mm) as shown in Figure 11.11.
Floor finishes in a facility must be firm and slip-resistant and should provide easy access throughout the building. If there is a change in level, the transition must meet the following requirements. If the change is less than 1/4 inch (6.4 mm), it may be vertical and without edge treatment. If the change in level is between 1/4 inch (6.4 mm) and 1/2 inch (12.7 mm), it must be beveled and its slope no greater than 1:2. Changes greater than 1/2 inch change the classification to a ramp, which must then meet the requirements outlined in the previous section. Bathroom floors should have a nonslip finish.
Door handles are also required to have a textured surface if they are part of a door that leads to an area that might prove dangerous to a blind person, including doors to loading platforms, boiler rooms, and stages.
Telephones are one of the easiest building elements to make accessible. They should be positioned so that they can be reached by a person in a wheelchair. Accessible telephones may be designed for either front or side access. In either case a clear floor space of not less than 30 inches (762 mm) by 48 inches (1220 mm) is to be provided. Telephones should have pushbutton controls and telephone directories that are accessible by a person in a wheelchair.
Title III stipulates that in new construction at least one TTY is to be provided inside any building that has four or more public pay telephones (counting both interior and exterior phones). A TTY must also be provided whenever there is an interior public pay phone in a stadium, convention center, hotel with a convention center, covered shopping mall, or hospital emergency, recovery, or waiting room. Title III also stipulates that one accessible public phone must be provided for each floor of new construction, unless the floor has two or more banks of phones, in which case one accessible phone should be provided for each bank.
There are restrictions on objects and building elements that project into corridors and other walkways, because they present a hazard for visually impaired people. There are no restrictions on protruding objects where their lower edge is less than 27 inches (686 mm) above the floor, because these can be detected by a person using a cane. However, protruding objects cannot reduce the clear width required for an accessible route or maneuvering space, and a guardrail or other barrier must be provided for areas adjacent to accessible routes where the vertical clearance is reduced to less than 80 inches (2 m).
Signage should give clear guidance for visually impaired people to emergency information and general circulation directions. Of importance in evaluating signage criteria is the ability to be viewed by people with low vision (20 percent of normal) from a distance of 30 feet (9.14 m). Signage is also required for elevators and handicapped-accessible entrances/exits, toilets, and other locations. For optimum clarity, adequate luminescence should be provided. Contrasting colors can also enhance legibility—70 percent or more contrast between letters and background is recommended.
The ANSI standards specify the width-to-height ratio of letters and how thick the individual letter strokes must be. They also require that characters, symbols, or pictographs on tactile signs be raised 1/32 inch (0.79 mm). If accessible facilities are identified, the international symbol of accessibility must be used (Figure 11.13). Braille characters must be Grade 2.
The ADA Accessibility Guidelines 4.1.3(14) state that, if emergency warning systems are provided, they shall include both audible alarms and visual alarms complying with 4.28. Audible alarms must produce a sound that exceeds the prevailing sound level in the room or space by at least 15 decibels. Visual alarms must be flashing lights that have a flashing frequency of about one cycle per second.
All elevators must be accessible from the entry route and all public floors and must comply with the applicable codes for elevators and escalators. Elevators must be provided with handrails fixed 32 inches above the floor on all three sides of the cab. Minimum cab size should be 67 inches (1.7 m) to allow a wheelchair to maneuver (Figure 11.14). Both visual and audible hall signals are important to inform elevator passengers where an elevator is and in which direction it is going. This is particularly important at elevator banks comprising more than one car. Elevator controls should comply with ANSI A117.1 standards regarding visual, tactile, and audible controls.
Minimum Dimensions of Elevator Cars
represent the vertical locations of the door reopening device not requiring contact.
represent the vertical locations of the door reopening device not requiring contact.
Hoistway and Elevator Entrances
Figure 11.14 Minimum dimensions for elevator cabs (source: 28 CFR Ch.1, Pt. 36, App.A, Fig.22, 20, 7-1-94 Edition).
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