Helonic is an AI construction drawing analysis platform for people check restroom stall layouts during plan review. The enlarged restroom plan and the accessibility schedule have to use different marks for the two stalls
A restroom with six or more water closets and urinals combined needs an ambulatory accessible stall in addition to the wheelchair accessible stall, and the two have different dimensions, doors, and grab bars. Helonic checks that both stalls are drawn and marked. The wheelchair stall is at least 60 inches wide. The ambulatory stall is 35 to 37 inches wide with grab bars on both sides. The miss is a plan that draws two stalls but uses one mark or one schedule row, so the ambulatory stall gets built to the wrong layout or not at all.
Under the 2010 ADA Standards Section 213.3.1, where toilet compartments are provided, at least one has to be wheelchair accessible. Where six or more toilet compartments, or a combination of six or more water closets and urinals, are provided in a toilet room, at least one ambulatory accessible compartment is required in addition to the wheelchair stall. The IBC uses the same trigger in Chapter 11.
Count the urinals. A men's room with four stalls and two urinals reaches six fixtures and needs both stall types.
Both stalls come from Section 604.8 of the 2010 ADA Standards. They share a name and very little else.
| Feature | Wheelchair stall | Ambulatory stall |
|---|---|---|
| Width | 60 inches minimum | 35 to 37 inches |
| Depth | 56 inches minimum with a wall-hung water closet, 59 inches with a floor-mounted one | 60 inches minimum |
| Water closet centerline | 16 to 18 inches from the side wall | 17 to 19 inches from the side wall |
| Door | Self-closing, doesn't swing into the required stall area, and located near the side away from the water closet | Self-closing, doesn't swing into the required stall area |
| Grab bars | Side wall and rear wall | Both side walls |
| Toe clearance | Required at the front partition and at least one side partition unless the stall is oversized | Not required |
Partition and accessory suppliers build from the toilet partition plan and the toilet accessory schedule. If both accessible stalls carry the same mark, or the schedule lists one accessible stall type with a quantity of two, the ambulatory stall either gets the 60 inch layout, which no longer fits the row, or it becomes a standard stall with grab bars added.
Schedules that disagree with plans are one of the most common drawing conflicts. The schedule verification feature covers how Helonic compares them.
Comparing a schedule to the plan it describes is a core step in how to review construction drawings. Single-user rooms are covered in accessible toilet room clearances, and the ADA accessibility guide covers the rest of the building.
Count fixtures on the plumbing plan, not the architectural plan. When plumbing adds a urinal to meet the fixture count, the room can cross six fixtures without anyone revisiting the stall layout.
Helonic reads the enlarged restroom plans, the toilet accessory schedule, and the plumbing fixture schedule together. It flags a room with six or more fixtures and no ambulatory stall, two accessible stalls sharing one mark, and an ambulatory stall drawn outside the 35 to 37 inch range. 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 schedule says two accessible stalls, the partition shop drawing shows two 60 inch stalls, and the row no longer fits. The ambulatory stall needed its own mark from the start.”
Common finding in restroom layout and schedule 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 213.3.1, 604.2, and 604.8. Local ICC A117.1 editions can differ, so check the adopted edition.
Last reviewed by Manas Gandhi · October 11, 2026
Related references for accessibility and restroom review.
Single-user room clearances and door swing.
Accessibility requirements across the drawing set.
Fixture counts and the fixture schedule.
The fixture symbols on the enlarged plan.
Plumbing items that fail plan check.
A systematic approach to catching drawing errors before construction.