Helonic is an AI construction drawing analysis platform for people check accessible toilet rooms during plan review. The door swing, the grab bars, and the lavatory have to stay out of the wheelchair clear floor space
An accessible single-user toilet room passes review when the enlarged plan shows a 60 by 56 inch clearance at the water closet with no lavatory in it, a turning space, grab bars on the side and rear walls, and a door that does not swing into the clear floor space of any fixture. Helonic checks those clearances on the enlarged plan. The 2010 ADA Standards and ICC A117.1 set these numbers. The miss is a room drawn at the minimum size, then a door, a lavatory, or a thicker wet wall takes back the clearance.
The 2010 ADA Standards set the federal baseline, and most building codes reach similar requirements through IBC Chapter 11 and ICC A117.1. Check the A117.1 edition your jurisdiction adopted, since newer editions changed some clearances. The numbers below are from the 2010 ADA Standards.
| Element | Requirement | Section |
|---|---|---|
| Water closet clearance | 60 inches wide from the side wall, 56 inches deep from the rear wall | 604.3.1 |
| Water closet centerline | 16 to 18 inches from the side wall | 604.2 |
| Side grab bar | 42 inches long minimum, 12 inches maximum from the rear wall, extending 54 inches minimum from the rear wall | 604.5.1 |
| Rear grab bar | 36 inches long minimum, extending 12 inches on one side of the centerline and 24 inches on the transfer side | 604.5.2 |
| Grab bar height | 33 to 36 inches to the top of the gripping surface | 609.4 |
| Lavatory | Rim 34 inches maximum, knee clearance 27 inches minimum high | 606.3, 306 |
| Turning space | 60 inch circle or T-shaped space | 603.2.1, 304 |
| Door swing | Does not swing into the clear floor space or clearance of any fixture | 603.2.3 |
| Mirror over lavatory | Bottom of reflecting surface 40 inches maximum above the floor | 603.3 |
Section 604.3.2 lets the water closet clearance overlap the water closet, its grab bars, dispensers, sanitary napkin disposal units, coat hooks, shelves, accessible routes, the clear floor space at other fixtures, and the turning space. No other fixture or obstruction can sit inside it. Under the 2010 ADA Standards, that means the lavatory can't be inside the 60 by 56 inch area.
Section 603.2.3 says doors can't swing into the clear floor space or clearance of any fixture. In a single-user room, the door can swing into it if a 30 by 48 inch clear floor space is provided inside the room beyond the arc of the door swing.
Fixture tags and wall thicknesses live on the plumbing drawings. Larger restrooms with stalls have their own rules, covered in ambulatory vs wheelchair accessible toilet stalls.
Drawing required clearances on the plan is a basic step in how to review construction drawings. The ADA accessibility guide covers the rest of the building.
Dimension to finished faces. A room that works at face of stud loses some width on every tiled wall, and a 60 inch clearance drawn to stud can end up under 60 inches after finishes.
Helonic reads the enlarged plans, the interior elevations, and the plumbing sheets for each accessible toilet room. It flags a lavatory inside the water closet clearance, a door swing over a fixture clearance, grab bars shorter than required, and a wet wall that shrinks the room. The accessibility checks cite the sheet for each finding.
Findings are decision support. The architect decides what changes. For how this review fits a project, see AI for construction drawings.
Practitioner insight
“The architect dimensions the room at 60 inches clear, the plumbing engineer thickens the wet wall for a carrier, and the room loses four inches that nobody puts back.”
Common finding in architectural and plumbing coordination review.
Manas is the co-founder and CTO of Helonic, where he leads engineering and AI research for construction drawing analysis. He works directly with structural, MEP, civil, and fire protection engineers to translate the way they review drawings into AI systems that flag the issues that actually matter in the field. Before Helonic, he built machine learning pipelines for technical document understanding and has spent the last several years interviewing licensed design engineers and discipline leads to ground product decisions in real practice rather than industry assumptions.
How this page was researched: Requirements were checked against the 2010 ADA Standards for Accessible Design, Sections 603, 604, 606, and 609. ICC A117.1 editions adopted by local codes can differ, so check the adopted edition.
Last reviewed by Manas Gandhi · October 10, 2026
Related references for accessibility and plumbing review.
When a multi-stall restroom needs both stall types.
Accessibility requirements across the drawing set.
Fixture tags, carriers, and wet walls.
The fixture symbols on the enlarged plan.
Plumbing items that fail plan check.
A systematic approach to catching drawing errors before construction.