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Building Code Reference

Got a CRC R318.3 correction?

Door landing requirements

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 R318.3 requires a landing or floor on each side of every exterior door in a California residence. The landing must be at least 36 inches deep in the direction of travel and at least as wide as the door. At the required egress door, the interior landing cannot drop more than 1-1/2 inches below the top of the threshold. The exterior side has more room: the landing can be up to 7-3/4 inches below the threshold, but only when the door doesn't swing out over that landing.

How to fix it

  1. Dimension every exterior door landing on your floor plan

    Add a landing callout at each exterior door showing depth (minimum 36 inches measured in the direction of travel) and width (minimum equal to the width of the door served). This includes back doors, side entries, sliding doors, French doors, and patio doors. If the landing is a concrete slab or existing deck, show it with a dimension string. Reviewers can't approve what they can't measure on the drawings.

  2. Verify the interior landing height at the egress door

    At your required egress door (typically the main entry or the door providing the primary egress path), measure the vertical distance from the top of the threshold down to the finished floor surface on the interior side. That drop cannot exceed 1-1/2 inches. If you have a recessed entry, sunken foyer, or any floor level change inside that door, note the finished floor elevation on the plans and show the threshold elevation as a reference. The plan-checker is looking for this specific number.

  3. Check the exterior threshold drop and door swing direction

    On the exterior side of the required egress door, the landing can sit up to 7-3/4 inches below the threshold — but only when the door does NOT swing outward over that landing. If the door swings out over the landing, the landing can be no more than 1-1/2 inches below the threshold; the 7-3/4-inch allowance no longer applies. Other exterior doors may have landings up to 7-3/4 inches below the threshold. Show the exterior landing elevation on your site plan or a detail. Note the door swing direction on the floor plan — the reviewer cross-references this with the landing height.

  4. Add a landing detail for any problematic threshold condition

    If your threshold condition is unusual (sloped grade, stepped entry, multi-level deck), add a section cut or detail at 1/4"=1' or larger. Show the threshold elevation, the landing surface elevation, the direction of door swing, and the landing depth. Label the vertical dimension explicitly: 'Landing 1-1/4" below threshold (interior)' or 'Landing 6" below threshold (exterior, door swings in).' A clear detail eliminates the back-and-forth with the plan-checker.

  5. Confirm landing width equals or exceeds the door width

    The landing width must be at least as wide as the door. A 3-0 door has a clear opening around 34-1/2 inches, but the code requires the landing width to match the full door width, not just the clear opening. On your floor plan, dimension the landing width with a note tying it to the door: 'Landing width = door width (3'-0" minimum).' If a wall, column, or railing narrows the usable landing, show those constraints and confirm the remaining width still meets the requirement.

  6. Tag sliding and French doors as exterior doors on your drawings

    R318.3 applies to any exterior door, not just hinged egress doors. Sliding glass doors, bi-fold doors, and French doors all need compliant landings on both sides. If your plans show these as window or wall openings rather than doors, update the tags to identify them as exterior doors and add the landing dimensions. The distinction matters because plan-checkers check every door tag for landing compliance.

  7. Cite the corrected dimensions in your resubmittal response letter

    In your response to the corrections letter, reference R318.3 by number and point the reviewer to the sheet where you've added the required dimensions. Include a brief correction response note: 'R318.3 — landing dimensions added to A1.1, see detail 3/A4. Interior landing is 1" below threshold, exterior landing is 5-1/2" below threshold. Door swings in.' Reviewers on second submittals are looking for a fast confirmation that the flagged item was addressed. Give them the numbers up front.

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Why you got flagged

Plan-checkers flag R318.3 corrections most often because the landing at an exterior door isn't dimensioned on the plans at all. If your site plan or floor plan doesn't show a landing at the back door, patio door, or side entry, the reviewer has no way to confirm it meets the 36-inch depth requirement. No dimension, no approval. This is the single most common reason this correction shows up in a resubmit packet.

The other scenario is an interior landing that's too low at the egress door. Some plans show a step-down from the threshold into the interior — a recessed entry, a sunken foyer, or a transition to a lower floor level. If that drop exceeds 1-1/2 inches, the plan-checker will flag it. This catches a lot of contractors off guard because the exterior threshold-to-landing drop is much larger (up to 7-3/4 inches), and people apply the exterior rule to the interior by mistake.

A third scenario involves doors that swing out over the exterior landing. If the door opens outward over the landing, the 7-3/4-inch drop allowance does not apply — the landing must be at or very close to threshold height. The bigger gotcha: if that outswing door's landing still doesn't have dimensions on the plans, the reviewer fails it for missing documentation regardless of actual site conditions.

Sliding doors and French doors sometimes get missed entirely. Contractors treat them as wall openings rather than egress doors, so neither the landing dimensions nor the threshold height difference makes it onto the drawings. Plan-checkers don't guess — if it's not shown, it's flagged.

The official code

2025 California Residential Code, Part 2.5 — Building Planning (door and egress provisions)

Read the source →

Common questions

Does R318.3 apply to every exterior door or just the front door?
Every exterior door. R318.3 doesn't distinguish between front entry, back door, side door, sliding patio door, or French door. All of them need a landing at least 36 inches deep in the direction of travel and at least as wide as the door. The most common miss is the back patio or side yard door — it gets treated as a window on the plans and never gets a landing dimension called out.
What's the maximum step-down from the threshold to the interior landing?
1-1/2 inches at the required egress door. This is the rule that surprises most contractors. The interior side of your primary egress door has very little tolerance — the floor on the inside can be at most 1-1/2 inches below the top of the threshold. Sunken foyers, recessed entries, and floor level changes just inside the door all need to be checked against this number. If you've got more than 1-1/2 inches of drop, you either need to raise the floor or redesign the entry.
How far below the threshold can the exterior landing sit?
Up to 7-3/4 inches — but only when the door does not swing outward over the landing. If the door swings in, the landing can drop up to 7-3/4 inches below the threshold. If the door swings out over the landing, that allowance disappears: the landing must be at or very close to threshold height. Beyond 7-3/4 inches on an inswing door, the exterior landing is out of compliance. Most standard stoops fall within this range, so the exterior rule is rarely a problem — the interior 1-1/2-inch rule is the one that generates corrections.
Does R318.3 apply to ADU exterior doors?
Yes. ADU permits go through full residential plan check and R318.3 applies to every exterior door on the ADU, including the primary entry, any secondary exit, and patio or deck doors. ADU corrections letters frequently cite R318.3 because the unit's exterior door landing gets squeezed by setback constraints or a small yard, and the landing depth isn't dimensioned on the submitted plans.
Can the landing be a wood deck or does it have to be concrete?
The landing can be any durable, weather-resistant surface — concrete, masonry pavers, a wood deck, or a composite deck platform. The code specifies landing dimensions (36 inches deep, door-width wide) and the threshold height relationship, not the material. What matters for plan check is that the material is identified on the plans and the dimensions are shown. A wood deck landing is fine; a wood deck landing with no dimensions called out will get flagged.
What if site grade makes a 36-inch landing impossible to build?
Talk to your plan-checker before resubmitting. R318.3 requires the 36-inch landing, and there's no code exception for sloped sites. If grade constraints make a conforming landing structurally difficult, the solution is usually a graded landing pad, a small concrete apron, or a deck platform that achieves the 36-inch depth. Some jurisdictions will require a variance if the site truly can't accommodate the landing. Don't leave this as a field-verify note on the plans — reviewers will hold the permit until it's resolved on paper.
The correction letter cites R318.3 but I have a landing — what did I miss?
The landing probably exists on site but isn't dimensioned on the plans, or the threshold height difference isn't noted. Plan-checkers work from the drawings, not from site visits. If your plans don't show the landing depth, width, and the interior threshold step (must be 1-1/2 inches or less at the egress door), the reviewer can't confirm compliance. Even if the real landing is perfect, the correction stands until the plans say so. Fix the drawings.

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