SEAC ASCE 7-22 Wind and Tornado Load Recommendations for Colorado

Colorado is a Special Wind Region state. That means the standard ASCE 7-22 national wind speed map does not give the final answer for every Front Range location. The SEAC guidance document explains when a local wind study is needed and what values engineers use as a starting point.

What this source says

SEAC published its ASCE 7-22 wind guidance to help Colorado engineers and building officials apply the 2024 IBC and IRC wind provisions correctly in Colorado. The document addresses:

The application of ASCE 7-22 wind and tornado load provisions in Colorado, with specific guidance on Special Wind Region (SWR) designations, local wind speed determination for exposed sites, and the wind load methodology applicable to Front Range jurisdictions adopting the 2024 IBC and IRC.

Special Wind Region (SWR) designation. ASCE 7-22 marks portions of Colorado as Special Wind Regions. Within an SWR, the national wind speed map value of 115 mph may not capture local wind conditions. Mountain passes, exposed ridges, canyon exits, and other terrain features can produce local wind speeds well above the regional average.

Front Range default. For most of the Denver urban corridor (Denver, Aurora, Lakewood, Arvada, Westminster, Longmont, Fort Collins), the SEAC guidance confirms that the design Vult is 115 mph with Exposure C as the typical condition. These values match the 2025 Denver Residential Code and Jefferson County design criteria.

Mountain and foothills sites. Sites in the foothills west of I-25 may be in an SWR zone. For those locations, the SEAC guidance recommends a local wind study or use of the Colorado Department of Transportation wind speed data for the specific site corridor. A garage door for a home on a ridge above Golden, for example, may need a higher wind rating than 115 mph.

Tornado provisions. ASCE 7-22 introduced explicit tornado load provisions. The SEAC guidance addresses how these apply in Colorado. Colorado has tornado activity, but it is lower intensity than the central plains. The SEAC document provides guidance for when tornado provisions govern over standard wind provisions.

When it applies

Residential projects in Denver and suburbs. Most Front Range residential sites are not in a terrain-exposed SWR location. Vult 115 mph at Exposure C applies. This produces a design pressure for a standard 16x7 garage door of about 20 to 22 psf.

Foothills and mountain communities. Any project at an exposed ridge, canyon mouth, or mountain pass location should check the SEAC guidance for SWR applicability. A site in Evergreen, Golden foothills, or the Poudre Canyon area may need a higher design wind speed.

Commercial projects requiring engineer of record sign-off. Commercial building permits in Denver and other Front Range cities require a structural engineer. The engineer uses the SEAC ASCE 7-22 guidance to confirm the design wind speed for the site before sizing the garage door opening and wind-rated door.

Checking a door wind rating against local conditions. If you have a door's rated design pressure (from its ANSI/DASMA 108 test label) and want to confirm it is adequate for your site, you need to know the required design pressure first. The SEAC guidance is part of that calculation chain.

What this means for you

For most Denver metro homes: 115 mph Vult Exposure C is the right starting point. Most commercial-grade residential doors rated at 20 to 24 psf cover this requirement for standard 16-foot wide by 7-foot tall openings.

For exposed sites: do not assume the map value applies. Ask your contractor to confirm that the site is not in an SWR zone before selecting a door. An undersized door on an exposed ridge is a real risk.

For engineering submittals: if Denver CPD asks for wind design documentation, the engineer will use ASCE 7-22 with the SEAC guidance to confirm the site design pressure. The door's ANSI/DASMA 108 test label must match or exceed that value.

G Brothers serves projects across the Front Range, including both urban and foothill locations. We can connect you with a structural engineer when a site-specific wind study is needed.

Full text and source

The SEAC ASCE 7-22 guidance document is at https://www.seacolorado.org/docs/ASCE_7-22_Final.pdf.

The SEAC guidance is a professional recommendation document, not a code provision itself. The binding wind design requirements come from ASCE 7-22 as adopted by the applicable local code. Confirm the required design wind speed for your site with a licensed structural engineer.