Bathroom stall dimensions, also referred to as water closet or toilet compartment sizes, are regulated by building codes to ensure usability, accessibility, and compliance with health and safety requirements.

Which occupancies are subject to stall dimension requirements

Bathroom stall dimensions are regulated across most occupancies in the International Building Code (IBC), International Plumbing Code (IPC), and ICC A117.1 Accessibility Standard. Stall requirements apply in:

Assembly occupancies (stadiums, theaters, auditoriums)
Educational facilities (K–12 schools, colleges, universities)
Institutional occupancies (hospitals, nursing homes, correctional facilities)
Residential occupancies with shared restrooms (dormitories, hotels, multifamily)
Business and mercantile occupancies (office buildings, retail stores, shopping centers)
Industrial facilities with required employee restrooms
Mixed-use developments that combine public and private uses

In short, any public or employee-serving restroom is regulated.

Which spaces are regulated under stall dimension requirements

The following spaces are subject to restroom stall sizing rules:

Public bathrooms in all occupancy groups
Employee restrooms, including single-user and multi-user toilet rooms
Accessible water closet compartments required per ADA Standards
Family/assisted-use restrooms (where required by IBC Section 1109.2.1)
Specialty areas such as healthcare patient bathrooms (which follow both IBC and FGI Guidelines)

Explicit exemptions or exceptions

Not all toilets or water closets require code-regulated stalls:

Private dwelling unit bathrooms (IRC governs, not IBC)
Single-user bathrooms with a door that swings outward
Temporary structures with limited use (IBC Chapter 31)
Agricultural buildings not intended for public use
Certain accessory storage mezzanines where plumbing fixtures are not required

Special conditions

Retrofits in existing buildings

When restrooms are renovated, at least one stall must be upgraded to meet ADA and ICC A117.1 dimensions. Other stalls may remain nonconforming if technically infeasible, provided overall accessibility is maintained (IBC Section 3411).

Historic preservation

Historic buildings must comply “to the maximum extent feasible” without destroying character-defining elements. In some cases, alternative methods are allowed (ADA Standards 202.5).

Nonconforming pre-code layouts

Pre-code or pre-ADA bathrooms are allowed to remain until altered. At the point of alteration, at least one accessible stall must be added.

Mixed-use buildings

For developments with combined uses (e.g., retail with apartments above), restrooms serving the public areas must meet IBC/ADA stall dimensions. Dwelling unit bathrooms remain governed by IRC or HUD accessibility guidelines.

Overlapping regulations

IBC/IPC: Governs plumbing fixture count, minimum stall size, and compartment layout (IBC Section 2902, IPC Chapter 4).
ICC A117.1: Defines maneuvering clearances and stall sizes for accessibility.\
ADA Standards: Federally enforceable accessibility requirements.

NFPA 101 (Life Safety Code): Addresses egress to and from restrooms but defers to accessibility codes for stall sizing.

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Stall dimension requirements table

Requirement

Typical Code Citation

Performance Value/Range

Design Rationale

Inspection Notes

Standard stall width

IPC Section 405.3.1

30–36 inches clear width

Allows user entry and fixture clearance

Check centerline of WC to partition spacing

ADA accessible stall width

ADA Standards 604.8.1.1

Minimum 60 inches wide

Provides side transfer for wheelchair users

Verify grab bar location and 60-inch minimum

ADA stall depth (wall-mounted WC)

ADA Standards 604.8.1.2

56 inches deep

Ensures wheelchair turning and clearance

Depth must be measured from back wall

ADA stall depth (floor-mounted WC)

ADA Standards 604.8.1.2

59 inches deep

Accommodates longer projection fixtures

Confirm depth to partition

Ambulatory stall width

ICC A117.1 Section 604.8.2

35–37 inches

Serves users with crutches or walkers

Must include parallel grab bars

Door clearance

ADA Standards 404.2.3

32 inches clear opening

Ensures wheelchair passage

Door must swing outward or slide

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Summary

This guide covers stall dimension requirements in U.S. building codes for public and employee restrooms across all major occupancies. It does not apply to private dwelling unit bathrooms or exempt structures. Both IBC and ADA govern dimensions, with ICC A117.1 providing detailed technical requirements.

FAQs

1. What is the minimum bathroom stall size per code?
The minimum standard stall is typically 30 inches wide by 60 inches deep, but accessible stalls must be 60 inches wide with depth varying between 56 and 59 inches depending on fixture type.

2. Are ADA stall dimensions different from IBC requirements?
Yes. IBC sets baseline dimensions, but ADA requires larger accessible compartments with maneuvering clearances. ADA is federally enforceable.

3. Do all restrooms need an ADA stall?
Yes, in public and employee restrooms at least one stall must comply with ADA Standards.

4. Can existing noncompliant stalls remain in use?
Yes, if no alterations are made. Once altered, at least one stall must be upgraded to ADA requirements.

5. What is an ambulatory stall?
An ambulatory stall is narrower than a wheelchair stall (35–37 inches wide) and is designed with parallel grab bars for people using crutches or walkers.

References

ICC (IBC 2021) – https://codes.iccsafe.org/codes/ibc
ICC (IPC 2021) – https://codes.iccsafe.org/codes/ipc
ADA Standards for Accessible Design (2010) – https://www.ada.gov/resources/2010-ada-standards/

ICC A117.1 Accessible and Usable Buildings and Facilities – https://codes.iccsafe.org/codes/icc-a117-1

This content is for informational purposes only, based on publicly available sources. It is not official guidance. For any building or compliance decisions, consult the appropriate authorities or licensed professionals.

Stall dimensions: Scope of application in U.S. building codes