Larimer County requires Class 4 impact-resistant asphalt shingles county-wide for new construction, repairs over 25%, and replacements — one of only two Colorado jurisdictions in our survey with a hail mandate. Class A fire-rated coverings and an ice barrier are also required county-wide, and much of the county is designated high-wind (140+ mph). On the 2024 I-codes since January 2026.

Hail mandate	Class 4 impact-resistant asphalt shingles are required for all new construction, repairs over 25%, and roof replacements. Repairs reaching 25% of the roof trigger full replacement — Class A fire rated and Class 4 impact resistant.
Certification	A Roofing Certification form is required county-wide: the owner or contractor attests the ice barrier, the class of covering, and installation to the site design wind speed.
Ice barrier	Required county-wide, extending at least two feet inside the exterior wall line. Exceptions: metal panel roofs, membranes, and unheated detached accessory structures.
Permit & wind	Repairs under one square (100 sq ft) are exempt from permit. Much of the county is a High-Wind Area with ultimate design wind speeds of 140 mph or more — coverings must be rated and attached for the site wind speed.

Details to confirm with the county

We couldn't confirm the following from Larimer County's official pages. Check these with the county before you rely on them:

• Fort Collins, Loveland, and Estes Park permit through their own building departments — their rules differ.

Verified July 2026 · Source: Larimer County — Roofing handout (2024 I-codes, updated 01/06/2026)