IRC 2021 Section R301 — Design Criteria

Updated May 18, 2026

Residential design loads: roof live 20 psf, floor live 30–40 psf by room, ground snow by climate zone. Climate zone 5 (Flagstaff AZ, Reno NV) requires ground snow load per Figure R301.2(3).

Flagstaff ground snow: ~40 psf typical. Reno: 30 psf typical. Phoenix/Vegas/Tucson: 0 psf design snow.

category

Structural — Design Criteria

code body

IRC

code year

2021

adopted by

["az-flag","nv-ro"]

source url

https://codes.iccsafe.org/content/IRC2021P1/chapter-3-building-planning

SOURCES

🔗https://codes.iccsafe.org/content/IRC2021P1/chapter-3-buildi...

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