ADA Door Hardware Compliance: The Complete Guide to Thresholds, Handles, and Building Codes
A door can look completely normal and still fail an ADA inspection.
A threshold that's a quarter-inch too tall. A round knob instead of a lever. A handle mounted two inches too high. None of these are visible problems from across the room, but each one is enough to make an opening non-compliant - and each one is a fix that's far cheaper before the door ships than after an inspector flags it.
This guide breaks down what ADA compliance actually requires at the door - thresholds, hardware, mounting height, and force - so you can specify it right the first time.
Why ADA Door Compliance Matters
ADA requirements at doorways exist for one practical reason: a door that's technically operable isn't necessarily usable by everyone. A round knob that needs a twisting grip, a threshold tall enough to catch a wheelchair caster, or hardware mounted out of reach all create real barriers, even on a door that otherwise functions perfectly.
For contractors and building owners, non-compliance isn't just a fairness issue - it's a liability and inspection risk. Getting the threshold height and hardware type right at the spec stage avoids a costly retrofit later.
1. Threshold Height Limits
This is one of the most commonly missed requirements, largely because the margin for error is so small.
- Exterior doors: threshold height must not exceed 1/2 inch (12.7 mm).
- Interior doors: threshold height must not exceed 1/4 inch (6.4 mm) in most applications.
- Beveling requirement: any threshold edge higher than 1/4 inch must be beveled, with a slope no steeper than 1:2.
Thresholds are measured on both sides of the opening, and the higher side is what determines compliance - so an uneven slab can push an otherwise compliant threshold out of spec on one side. This is exactly where an adjustable, low-profile threshold earns its place on accessible openings - it can be fine-tuned to stay within height limits even when the surrounding floor isn't perfectly level.
2. Door Hardware: Lever, Not Knob
ADA doesn't specify an exact hardware shape - it specifies an operating requirement. Hardware must be operable with one hand, without tight grasping, pinching, or twisting of the wrist, and it must work with a closed fist.
In practice, this rules out standard round doorknobs entirely, since they require a twisting grip to operate. Compliant options include:
- Lever-style handles
- Push and pull bars
- Panic and exit devices
- U-shaped handles
A simple field test: if the hardware can be operated by pressing down or pushing with the side of a closed fist, it's likely compliant. If it requires gripping and rotating, it isn't.
3. Mounting Height
All operable hardware on an accessible door - levers, pulls, latches, exit devices - must be mounted between 34 and 48 inches above the finished floor, measured to the centerline of the operating mechanism, not the edge of the handle.
Standard commercial lever hardware is typically installed at 38 to 42 inches, which comfortably falls within the compliant range. Anything below 34 inches or above 48 inches fails, regardless of how compliant the hardware type itself is.
4. Opening Force
Interior hinged doors on an accessible route are limited to 5 pounds of force (5 lbf) maximum to open. The ADA Standards don't specify a maximum force for exterior doors, though many contractors target a similar range for consistency.
Fire-rated doors are the one area where this gets complicated. Fire code may require a stronger closing force than 5 lbf to ensure the door latches properly under fire conditions, which can conflict directly with the ADA force limit. The standard resolution is a low-energy power operator that provides hands-free, ADA-compliant access while the mechanical closer still meets the fire code's positive-latching requirement.
5. Door Closer Speed
Where a door closer is installed, it must be adjusted so the door takes at least 5 seconds to swing from the fully open (90-degree) position to 12 degrees from the latch. A door that closes too quickly is both a safety hazard and an accessibility failure for anyone who needs more time to clear the opening.
ADA Door Compliance at a Glance
| Requirement | Standard |
|---|---|
| Exterior threshold height | Maximum 1/2 inch (12.7 mm) |
| Interior threshold height | Maximum 1/4 inch (6.4 mm) |
| Threshold beveling | Required above 1/4 inch, slope no steeper than 1:2 |
| Hardware mounting height | 34 to 48 inches above finished floor |
| Interior door opening force | 5 lbf maximum |
| Door closer speed | Minimum 5 seconds from 90° to 12° |
| Hardware operation | One hand, no tight grasping, pinching, or twisting |
Common Compliance Failures
Most ADA door failures come down to a short list of repeat offenders:
- Round doorknobs instead of lever hardware
- Hardware mounted below 34 inches or above 48 inches
- Thresholds exceeding 1/2 inch, or missing the required bevel
- Uneven thresholds where one side exceeds the height limit even if the other doesn't
- Closers adjusted to swing shut faster than the 5-second minimum
Nearly all of these are addressed at the hardware selection stage - choosing a genuinely ADA-appropriate lever, mounting it at the correct height, and specifying a low-profile, adjustable threshold from the start rather than retrofitting after inspection.
FAQ
What is the maximum threshold height allowed under ADA?
Exterior thresholds must not exceed 1/2 inch, and interior thresholds must not exceed 1/4 inch. Any edge higher than 1/4 inch must be beveled with a slope no steeper than 1:2.
Are round doorknobs ADA compliant?
No. Round doorknobs require a twisting grip to operate, which does not meet the ADA requirement that hardware be operable with one hand without tight grasping, pinching, or twisting.
What height should ADA door hardware be mounted at?
All operable hardware must be mounted between 34 and 48 inches above the finished floor, measured to the centerline of the operating mechanism.
How much force can it take to open an ADA compliant door?
Interior hinged doors on an accessible route are limited to 5 pounds of force maximum. Fire-rated doors may exceed this if required by fire code, typically resolved with a power-assisted operator.
Do ADA requirements apply to both sides of the door?
Yes. Both the push side and pull side of a door in a public or commercial facility must meet the same force, height, and operability requirements.
Can an existing non-compliant door be retrofitted?
In most cases yes. Replacing round knobs with lever handles, adjusting or replacing the door closer, and installing a low-profile adjustable threshold are common, straightforward retrofits.
Have more questions? Visit our full FAQ page.
Final Thoughts: Build Compliance In From the Start
ADA door compliance comes down to a short, specific list of measurements - threshold height, mounting height, opening force, and hardware type. None of these are difficult to meet on their own, but they're easy to miss when hardware is chosen for looks or cost before checking it against the standard.
Specify lever hardware at the right height, a low-profile adjustable threshold, and a properly adjusted closer from the start, and ADA compliance stops being a punch-list item and becomes a normal part of the spec.