ADA bathtub requirements, measured: sections 607, 608 and 610
Direct answer: An ADA bathtub needs a clear floor space 30 inches wide along its full length (607.2), a permanent or removable seat whose top sits 17 to 19 inches above the floor (610.2), grab bars on the back and end walls with the upper back bar 33 to 36 inches high (607.4, 609.4), controls on an end wall, a hand shower on a hose of at least 59 inches, and water capped at 120°F (607.6).
Who has to follow these rules
The 2010 ADA Standards for Accessible Design apply to buildings covered by the Americans with Disabilities Act: shops, offices, hotels, medical offices, government buildings and similar places. Section 213.3.6 says that where a bathing facility has bathtubs or showers, at least one bathtub complying with 607 or one shower complying with 608 must be provided. Hotels, care facilities and housing run by public entities have their own scoping rules on how many accessible rooms they need.
A family home is a different situation. The ADA does not reach the private living areas of a house, which is why we wrote a separate page on what actually applies at home. The numbers below are still the best published benchmark for a bathroom that a wheelchair user has to work in, so they make a sensible reference for a home project too.
Clear floor space beside the tub (607.2)
This is the space where a wheelchair parks for a transfer and where a helper stands. It must be at least 30 inches wide and run the full length of the tub. When the tub has a permanent seat at the head end, the space must extend at least 12 inches beyond the head-end wall, so the wheelchair can line up with the seat. A lavatory that meets section 606 may sit at the control end of the clearance.
Schematic drawn from sections 607.2, 607.3 and 607.5 of the 2010 ADA Standards. Not to scale.
For comparison, the general wheelchair space in the Standards (305.3) is 30 by 48 inches, and a full turning space (304.3) is a 60-inch circle or a T-shape inside a 60-inch square. Bathrooms that only meet the tub clearance can still be hard to turn around in.
Seats (607.3 and 610)
Every ADA tub needs either a permanent seat at the head end or a removable in-tub seat. Section 610 sets the dimensions.
| Item | Requirement | Section |
|---|---|---|
| Seat height | Top of seat 17 in (430 mm) minimum, 19 in (485 mm) maximum above the bathroom floor | 610.2 |
| Removable in-tub seat depth | 15 in (380 mm) minimum, 16 in (405 mm) maximum; must be capable of secure placement | 610.2 |
| Permanent head-end seat depth | 15 in (380 mm) minimum, running from the back wall to or beyond the outer edge of the tub | 610.2 |
| Strength | Must take a 250 lb (1112 N) vertical or horizontal force at any point without exceeding allowable stresses | 610.4 |
The 17 to 19 inch range matters because it is close to the seat height of many wheelchairs, which makes a level, sideways slide possible. If your own chair sits higher or lower, the transfer tub guide explains how to match the heights.
Grab bars (607.4 and 609)
The layout depends on whether the tub has a permanent seat.
| Wall | Tub with a permanent seat (607.4.1) | Tub without a permanent seat (607.4.2) |
|---|---|---|
| Back wall | Two bars: one at 33 to 36 in above the floor, one 8 to 10 in above the tub rim. Each ends no more than 15 in from the head-end wall and no more than 12 in from the control-end wall. | Two bars, each at least 24 in long: one at 33 to 36 in above the floor, one 8 to 10 in above the rim. Each ends no more than 24 in from the head-end wall and no more than 12 in from the control-end wall. |
| Control end wall | One bar at least 24 in long at the front edge of the tub | One bar at least 24 in long at the front edge of the tub |
| Head end wall | None required (the seat is there) | One bar at least 12 in long at the front edge of the tub |
Section 609 then sets how every grab bar is built and mounted:
- Size: round bars 1¼ to 2 inches in outside diameter; other shapes no more than 2 inches across with a perimeter of 4 to 4.8 inches (609.2).
- Spacing: exactly 1½ inches between the bar and the wall, at least 1½ inches to objects below and at the ends, and at least 12 inches to objects above, except shower controls and fittings, which may be 1½ inches away (609.3).
- Position: horizontal, 33 to 36 inches above the floor to the top of the gripping surface, apart from the lower back-wall bar at a tub (609.4).
- Strength: a 250-pound force in any direction at any point on the bar, fasteners, mounting or wall behind it (609.8). Bars must not rotate in their fittings (609.6).
There are two exceptions. Grab bars may be left off a tub in a single-occupant bathing room reached only through a private office, and in residential dwelling units, as long as the walls are reinforced so compliant bars can be added later.
Controls, hand shower and water temperature (607.5 to 607.7, 309.4)
- Where the controls go: on an end wall, between the tub rim and the grab bar, and between the open side of the tub and the centerline of its width. Drain stoppers are exempt (607.5).
- How they work: usable with one hand, with no tight grasping, pinching or twisting of the wrist, and no more than 5 pounds of force (309.4).
- Hand shower: a spray unit on a hose at least 59 inches long that works both as a fixed head and as a hand-held shower, with an on/off control that has a non-positive shut-off. A slide bar must not block the grab bars (607.6).
- Temperature: 120°F (49°C) maximum at the spray unit (607.6). This protects people with reduced sensation in their legs, who may not feel water that is too hot.
- Enclosures: doors or screens must not block the controls or the transfer from a wheelchair, and there may be no track on the rim of the tub's open face (607.7). A standard sliding glass tub door on a rim track does not comply.
Section 608: transfer and roll-in showers, side by side
Many people deciding on a tub are also weighing a shower. Here are the three accessible shower types in the Standards, so you can compare footprints.
| Type | Inside size | Entry | Clearance outside |
|---|---|---|---|
| Transfer shower | 36 in by 36 in | 36 in wide minimum | 36 in wide by 48 in long, measured from the control wall |
| Standard roll-in | 30 in wide by 60 in deep minimum | 60 in wide minimum | 30 in wide by 60 in long along the open face |
| Alternate roll-in | 36 in wide by 60 in deep minimum | 36 in wide at one end of the long side | Not set by 608.2.3 |
Thresholds are limited to ½ inch in roll-in showers, and to ½ inch (beveled, rounded or vertical) in transfer showers, with a 2-inch allowance in some existing buildings (608.7). A transfer shower needs a seat (608.4), and its controls go on the side wall opposite the seat, 38 to 48 inches above the shower floor (608.5.1). Seats follow the same 17 to 19 inch height rule as tubs (610.3).
If you are leaning toward a shower, Aging Safely Baths publishes a detailed roll-in shower guide and sells a 40 by 38 inch Bestbath ADA transfer shower.
Where walk-in and transfer tubs fit
Read section 607 closely and you will notice it describes a conventional tub: a rim you transfer over, a seat at the head end or on a board, and bars on the walls. It does not mention tubs with doors. That has two practical consequences.
- In a public or commercial building, do not assume a walk-in tub counts as the required accessible tub. Its seat height, door and grab bars have to be checked against 607 and 610 by the designer, and the local code official has the final word. Section 607.7 is often the sticking point, because nothing may obstruct the transfer from a wheelchair.
- In a house, the ADA does not apply, so a door-style tub is judged only on whether it works for the bather. A wheelchair transfer tub with an outward-swinging door can be easier to use than a code-compliant standard tub, because the bather slides across at seat height instead of lifting their legs over a rim.
Aging Safely Baths lists its wheelchair transfer tub models with seat and door dimensions, which you can hold up against the numbers on this page.
Using these numbers in a house
Five numbers worth copying at home: 30 inches of clear floor beside the tub; a seat top 17 to 19 inches above the floor; grab bars that can take 250 pounds, mounted into blocking, not drywall; a hand shower on a 59-inch hose; and hot water limited to 120°F at the fixture.
The ADA's own exceptions for homes say the same thing in a different way: grab bars may wait, but the reinforcement behind the wall should go in during construction. If you are remodeling, ask for blocking around the whole tub even if you only install one bar today.
For the Fair Housing Act, Section 504 and building codes that do reach some homes, see ADA vs residential bathrooms. For room planning with a wheelchair, see our guide to accessible bathtub layouts.
Questions people ask us
What seat height does the ADA require for a bathtub?
Section 610.2 of the 2010 ADA Standards puts the top of a bathtub seat 17 inches minimum and 19 inches maximum above the bathroom floor. A removable in-tub seat must be 15 to 16 inches deep, and a permanent seat at the head end must be at least 15 inches deep.
How high do ADA grab bars go beside a bathtub?
The upper bar on the back wall sits 33 to 36 inches above the floor, measured to the top of the gripping surface (609.4). The lower back-wall bar sits 8 to 10 inches above the tub rim (607.4). Each bar must hold a 250-pound force (609.8).
How much clear floor space does an ADA bathtub need?
A space at least 30 inches wide running the full length of the tub (607.2). If the tub has a permanent seat at the head end, that space must run at least 12 more inches past the head-end wall. A lavatory is allowed at the control end of the clearance.
Do the ADA bathtub rules apply to walk-in tubs?
The 2010 Standards describe a standard tub with a seat and grab bars. They do not mention door-style walk-in tubs. In a public building, whether a particular door tub can count as the accessible tub is a call for the designer and the local code official. In a private home the ADA does not apply at all.
What water temperature does the ADA allow at a tub hand shower?
Bathtub shower spray units must deliver water at 120°F (49°C) maximum (607.6). The same section requires a hand shower hose at least 59 inches long that also works as a fixed shower head.
Sources
- U.S. Access Board, 2010 ADA Standards, section 607 Bathtubs, 608 Shower Compartments, 609 Grab Bars and 610 Seats.
- U.S. Access Board, 2010 ADA Standards, section 213 Toilet Facilities and Bathing Facilities, and 304 Turning Space, 305 Clear Floor Space and 309 Operable Parts.
- U.S. Department of Justice, 2010 ADA Standards for Accessible Design.
