Non-Digital and Built Environment Accessibility
The governing standards
In the U.S., the 2010 ADA Standards for Accessible Design set scoping (what must be accessible) and technical requirements (how). ABA standards cover federal facilities; state and local codes (often based on IBC/ANSI A117.1) may be stricter, and the stricter rule governs. Universal design's seven principles extend the same thinking to products and services.
Dimensions exam writers love
- Accessible route: 36 in minimum clear width; passing spaces 60×60 in every 200 ft.
- Doors: 32 in minimum clear clear width.
- Ramps: maximum slope 1:12, maximum 30 in rise per run, level landings, handrails 34–38 in.
- Turning space: 60 in diameter circle or T-shape.
- Reach ranges: unobstructed high forward reach 48 in, low 15 in.
- Grab bars: 33–36 in above the floor; water closet seats 17–19 in.
- Parking: car space 96 in wide with a 60 in access aisle; van-accessible space 132 in wide (or 96 in with a 96 in aisle) and van spaces are required in new lots.
- Signage: raised characters and braille, mounted 48–60 in to the baseline of the text, on the latch side.
- Detectable warnings at curb ramps and platform edges.
Traps
"Grandfathering" - there is no blanket exemption; existing elements compliant with earlier standards may enjoy a safe harbor, but alterations trigger upgrade duties. "Reasonable accommodation means any request must be granted" - no; undue burden and fundamental alteration exist but must be documented. "Wayfinding is a nice-to-have" - signage, contrast, and acoustics are regulated or strongly implied.
Worked example
A 60 in-wide corridor has a 90-degree turn. It needs a 60×60 in clear turning space at the corner, plus 36 in clear width continuing beyond it; furniture that narrows the path to 30 in breaks compliance even though the corridor itself is fine.