Accessible water closet: centerline 16-18 in from sidewall; 60 in × 56-59 in clear floor; grab bars on sidewall + rear
US Access Board ABA §604.3 / 604.5 Water closet clearancesDescription
Accessible water closets must be installed with the centerline 16-18 in from the adjacent sidewall (or partition for a privacy compartment). Clear floor space: 60 in wide × 56-59 in deep (deeper for floor-mount, shallower for wall-mount). A side grab bar at least 42 in long must be on the sidewall, starting no more than 12 in from the rear wall and extending at least 54 in from the rear wall. A rear grab bar at least 36 in long must be on the wall behind the toilet. Grab bars 33-36 in above the floor. Flush controls on the open (transfer) side.
Why this exists
These dimensions allow a wheelchair user to transfer from chair to toilet from the open side. Most residential bathrooms can't accommodate them retroactively — architects designing accessible primary baths should plan the 60 × 56 in clear floor + grab-bar blocking IN THE FRAMING (blocking behind drywall) even if grab bars aren't installed at construction (aging-in-place foresight).
Measurements
| Property | Operator | Value | Unit | Note |
|---|---|---|---|---|
centerlineMin | min | 16 | in from sidewall | Toilet centerline minimum from sidewall |
centerlineMax | max | 18 | in from sidewall | Toilet centerline maximum from sidewall |
clearFloorWidth | min | 60 | in | Clear floor space width |
sideBarLength | min | 42 | in | Side grab bar minimum length |
rearBarLength | min | 36 | in | Rear grab bar minimum length |
grabBarHeight | range | 33–36 | in AFF | Grab bar mounting height |
Categories
Source
Solver enforcement
Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.
Related directives
- Bathroom entry doorway · NKBA Bath 1
- Kitchen walkway and work-aisle widths · NKBA Kitchen 6
- Doorway swing clearance · NKBA Bath 2
- Clear floor space at fixtures · NKBA Bath 3
- Fixture clear-space overlap · NKBA Bath 4
Last reviewed 2026-05-15.