The standards
The measurements behind a safe, comfortable home, with the source for each one.
Why we use the ADA for homes
The Americans with Disabilities Act generally doesn't apply to private houses. But its 2010 Standards are the most widely tested set of accessibility measurements there is, so we use them as a guide. Your local building code still applies.
| Bathrooms | Target | What it means at home | Source |
|---|---|---|---|
| Grab bar height | 33–36 in | Measured to the top of the bar, beside and behind the toilet and in the shower. | ADA 2010, §609.4 |
| Grab bar diameter | 1¼–2 in | Round bars in this range are easiest to grip firmly. | ADA 2010, §609.2.1 |
| Space behind a grab bar | 1½ in | Enough room for a hand, but not enough for an arm to slip through. | ADA 2010, §609.3 |
| Toilet seat height | 17–19 in | Measured to the top of the seat. Easier to stand up from than a standard toilet. | ADA 2010, §604.4 |
| Toilet distance from side wall | 16–18 in | From the wall to the center of the toilet, so a side grab bar is in reach. | ADA 2010, §604.2 |
| Roll-in shower size | 30 × 60 in min. | Inside dimensions for a shower a wheelchair can roll into. | ADA 2010, §608.2.2 |
| Knee space under a sink | 27 in high | Lets someone sit at the sink. Pipes underneath should be covered. | ADA 2010, §306.3 |
| Doors, floors and paths | |||
| Clear opening of a doorway | 32 in min. | With the door open 90 degrees. 36 in is more comfortable for a wheelchair. | ADA 2010, §404.2.3 |
| Doorway threshold | ½ in max. | Anything taller is a trip hazard and a barrier to wheels. | ADA 2010, §404.2.5 |
| Change in floor level | ¼ in | Up to ¼ in can be a straight edge. Up to ½ in needs a bevel. | ADA 2010, §303.2–303.3 |
| Space to turn a wheelchair | 60 in circle | Needed in at least one spot in rooms used from a wheelchair. | ADA 2010, §304.3.1 |
| Floor space for one person seated | 30 × 48 in | The space needed in front of a sink, counter or appliance. | ADA 2010, §305.3 |
| Tile grip on wet indoor floors | DCOF 0.42+ | Higher numbers mean more grip. Check the product sheet. | ANSI A326.3 |
| Ramps and stairs | |||
| Steepest ramp slope | 1 : 12 | One inch of rise for every 12 inches of length. Gentler is better. | ADA 2010, §405.2 |
| Highest rise per ramp run | 30 in | Longer ramps need a level landing to rest on. | ADA 2010, §405.6 |
| Handrail height | 34–38 in | Measured to the top of the rail, on ramps and stairs. | ADA 2010, §505.4 |
| Handrail diameter | 1¼–2 in | A rail you can wrap your hand around fully. | ADA 2010, §505.7.1 |
| Reach and controls | |||
| Comfortable reach range | 15–48 in | Above the floor. Keep everyday items, switches and controls in this band. | ADA 2010, §308.2.1 |
| Force to operate a control | 5 lbf max. | Handles, latches and switches should work without tight grasping or twisting. | ADA 2010, §309.4 |
Sources: 2010 ADA Standards for Accessible Design (U.S. Department of Justice) and ANSI A326.3 (dynamic coefficient of friction for hard surface flooring). Section numbers refer to the ADA Standards unless marked ANSI.