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Building Code Reference

Got a CRC R318.7.8 correction?

Handrail height and profile

For builders in California, Greater Seattle, the Las Vegas area, the Denver area and Kansas City · CrossBeam Permits

What this code requires, how to fix it, and how cities and counties review it

What this code requires

CRC R318.7.8 requires a handrail on at least one side of each flight of stairs with four or more risers, and CRC R320 sets its height and grip. Handrails must sit between 34 and 38 inches above the stair nosing, measured vertically (R320.2). A Type I grip is circular (1-1/4 to 2 inches in diameter) or non-circular with a perimeter of 4 to 6-1/4 inches and a maximum cross-section of 2-1/4 inches; a larger Type II profile needs finger recesses (R320.6). Single-family, ADU, and multi-unit residential permits all hit this section whenever stairs are part of the scope.

How to fix it

  1. Add a dimensioned stair section to the plan set

    Include a stair section drawing at 1/4"=1'-0" or larger that shows the handrail mounting height. Draw a vertical dimension line from the top surface of the stair nosing to the top of the handrail. Label it explicitly: 'Handrail height: 34" min / 38" max above nosing.' Place this dimension on both the stringer side and the wall side if handrails are on both.

  2. Specify the handrail profile with actual dimensions

    Don't just call out a product name or say 'handrail per code.' Show the profile geometry. If you're using a round pipe or rod, confirm the diameter is between 1-1/4" and 2". If the profile is non-circular (oval, D-shape, square with rounded corners), document the full perimeter and the widest cross-section dimension. For a Type I profile, perimeter must be between 4" and 6-1/4" and max cross-section is 2-1/4"; a larger profile must be Type II with finger recesses on both sides (CRC R320.6). A quick sketch or manufacturer spec sheet attached as an exhibit on the sheet works fine.

  3. Note clearance and return requirements from CRC R320

    R318.7.8 requires the handrail; the details live in CRC R320, and plan-checkers check them in the same review. CRC R320.4 requires at least 1-1/2 inches of clear space between the wall and the handrail — show this on your bracket detail. CRC R320.5 requires each handrail end to return continuous to itself or toward a wall, guard or walking surface, with no more than a 1/4-inch gap at the wall. Address both alongside the height and profile fix so the stair detail is complete.

  4. Verify height throughout the full run including landings

    The 34-38 inch measurement applies at every point along the stair run, not just at a single reference point. On stairs with winders or a change in pitch, verify the dimension at the tightest point (fittings or bendings at winder and flight transitions may exceed 38 inches per R320.2). For stairs with an intermediate landing, show the height at the landing transition too, since a wall-mounted handrail often changes elevation here.

  5. Cross-check against guard requirements if height overlaps

    If your stair has a guard (required when the open side of the stair is more than 30 inches above grade or a floor), the top of the guard may also serve as the handrail. In that case, the combined guard/handrail must meet both the 34-38 inch handrail height range from CRC R320.2 and the guard height requirement under CRC R321.1.2, which in California sets 34 to 38 inches for a guard whose top serves as the handrail (34 inches minimum for other guards on the open side of a stair). Guards that double as handrails must satisfy both, so check R321.1.2 alongside R320.2.

  6. Resubmit with a revision cloud around the updated detail

    When you resubmit, put a revision cloud around every sheet that changed and add a delta triangle with a revision number. On the stair section, bubble the handrail height dimension and the profile callout so the plan-checker goes straight to the fix. A clean, targeted resubmit on a single correction like this is much faster to process than a full plan set revision.

Take the CRC R318.7.8 fix steps with you

All 6 steps in one email, so you have them on site instead of on this page.

Why you got flagged

Plan-checkers flag R318.7.8 most often because the stair section detail is missing or incomplete. A lot of submittals show the stair geometry (rise, run, total flight height) but never call out the handrail mounting height. The plan-checker can't verify 34 to 38 inches from the nosing line without a dimensioned section, so the correction letter goes out.

A second common scenario is a handrail spec that names a product without confirming the profile dimensions. Builders often write "wood handrail per code" on the plans, which tells the plan-checker nothing about whether the chosen profile is actually graspable. A 2x4 flat cap rail on a deck stair, for example, has a cross-section well over 2-1/4 inches and fails the non-circular rule, even though it looks fine on site.

ADU projects get flagged here more than any other residential type because the stair is often squeezed into a tight footprint, and the designer draws the stair layout but skips the railing detail sheet entirely. When the railing detail does appear, it sometimes shows a decorative profile (oval, beveled, fluted) without documenting the perimeter measurement, which is what R320.6 actually enforces.

Remodels and additions that touch an existing stair can also trigger this correction. If the scope of work includes any modification to the stair structure or finishes, the plan-checker will often apply current code to the whole run, including the handrail. An older home with a 2-1/2 inch round rail that was fine under a previous edition may get flagged when the new plans arrive.

The official code

CRC R318.7.8 Handrails — 2025 California Residential Code (Title 24 Part 2.5)

Read the source →

Common questions

Does CRC R318.7.8 apply to ADU stairs?
Yes. R318.7.8 applies to all stairs serving a residential occupancy under the California Residential Code, including ADUs. If the ADU has a loft, a split-level, or any interior stair, a code-compliant handrail meeting the R320 height and profile requirements is required on stairs with four or more risers. The same 34-38 inch height range and graspability requirements apply. ADU projects are one of the more common sources of handrail corrections because the stair is often an afterthought in the design. Note: R318.7.8 sets when a handrail is required (four or more risers, at least one side); the CRC has no stair-width rule for handrails on both sides.
What counts as a graspable handrail profile under the CRC?
CRC R320.6 allows Type I and Type II profiles. Type I circular: outside diameter between 1-1/4 and 2 inches. Standard 1.5 inch Schedule 40 pipe clears this. A 2x4 or 2x6 laid flat does not. Type I non-circular: total perimeter between 4 and 6-1/4 inches, with a maximum cross-section dimension of 2-1/4 inches. Type II: a perimeter over 6-1/4 inches with a graspable finger recess on both sides. Many wood profiles (D-shaped, oval, square with rounded corners) can qualify if you document the dimensions. The key test is whether a normal adult hand can wrap around and grip it during a fall. Decorative cap rails and wide top rails typically fail Type I because the cross-section exceeds 2-1/4 inches, unless they are shaped with Type II finger recesses.
Where exactly do you measure the 34-38 inch handrail height?
Vertically, from the top of the stair nosing directly below the measurement point to the top surface of the handrail. You don't measure along the slope of the stair or perpendicular to the slope. It's a plumb (vertical) measurement. On a stair with uniform risers, the handrail will be parallel to the stair slope and the measurement will be consistent throughout. If the height drifts outside 34-38 inches at any point in the run, that's a violation.
Do handrails need to be on both sides of the stair?
Not always. CRC R318.7.8 requires a handrail on at least one side of each flight with four or more risers; it does not require both sides, and the CRC has no stair-width trigger for a second rail. Whichever handrails are present must meet the R320.2 height range (34-38 inches) and the R320.6 grip profile.
My stair has a decorative newel post. Does the rail have to meet the handrail rules all the way to the newel?
Under CRC R320.5 the handrail runs the full length of the stair flight, and height and profile must be maintained throughout. A newel post may interrupt it at a turn with winders, at a landing, or over the lowest tread, and a volute, turnout or starting easing may terminate over the lowest tread. Otherwise each end must return continuous to itself or toward a wall, guard or walking surface. The newel post itself doesn't need to be graspable, but the handrail must connect to it without leaving an open end projecting into the path of travel.
We're just repainting the stair. Do we need to bring the handrail up to current code?
Repainting alone doesn't trigger handrail compliance. Code upgrades are generally required only when the scope of work includes structural changes to the stair, new construction, or a significant alteration. That said, if you're pulling a permit for anything on the property and the plans show the existing stair, the plan-checker may flag the handrail if it's visibly non-compliant in the drawings. The trigger is the permitted scope, not painting. If your permit is for something unrelated and the stair doesn't appear on the plan sheets, this correction won't come up.

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