CodeMandatory
Stair riser height maximum 8.25 inches
Virginia USBC 2021 Amendment 19 (IRC R311.7.5.1)Description
The riser height shall be not more than 8.25 inches. The riser shall be measured vertically between leading edges of the adjacent treads. The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3/8 inch.
Why this exists
Higher than the IRC's 7.75" baseline — Virginia accepts a slightly steeper residential stair to accommodate retrofits + tight spaces. The 3/8" inter-riser variance enforces uniformity for trip-safety.
Measurements
| Property | Operator | Value | Unit | Note |
|---|---|---|---|---|
maxRiser | max | 8.25 | in | Maximum riser height |
maxVariance | max | 0.375 | in | Maximum variance between any two risers in a flight |
Categories
Life safetyCirculation
Applies to
- Jurisdiction: Virginia
Source
Virginia DHCDauthoritative
2021 Virginia Construction Code (Part I of USBC) (2021)
Section: Amendment 19 (IRC R311.7.5.1)
Published 2024-01-18 · last verified 2026-05-10
Solver enforcement
Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.
Related directives
- Garage / dwelling fire separation · IRC R302.6
- Habitable space minimum ceiling height · IRC R305.1
- Egress window net opening dimensions · IRC R310.2
- Stair riser, tread, and headroom · IRC R311.7
- Smoke alarms required throughout dwelling · IRC R314
Last reviewed 2026-05-10.