In recent years, Colorado has experienced multiple devastating wildfires in what has been termed the Wildland-Urban Interface or WUI. WUI is defined as areas where structures and other human development meet or intermingle with undeveloped wildlands or vegetative fuels. Population growth and expansion of urban development into traditionally non-urban areas have increasingly brought people into contact with wildfires. WUI is the fastest-growing land use type in the contiguous U.S.
CWRC Adoption
In May 2023, Colorado introduced Senate Bill 23-166, leading to the formation of a Wildfire Resiliency Code Board under the Division of Fire Prevention and Control. The goal of this Board is to improve safety and resilience against wildfires across communities in Colorado by promoting the adoption of relevant codes and standards. The initiative stemmed from a joint effort between the state legislature and firefighting professionals. On July 1, 2025, the 2025 Colorado Wildfire Resiliency Code (CWRC) was adopted.
The CWRC, as written, currently bans the use of natural wood products for exterior uses such as siding and decking. Long standing options for builders and homeowners such as Redwood, which carries a natural Class B flame spread rating, and Cedar, would not be allowed. This and other provisions of the CWRC will likely lead to higher housing costs and exacerbate housing shortages. Articles discussing concerns around higher housing costs and potential housing shortages can be read here:
Additionally, there are concerns that the Wildfire Resiliency Code Board failed to adequately incorporate stakeholder comments throughout the CWRC development process. One critical stakeholder is the wood products industry represented by the American Wood Council (AWC). Having had previous success in California, AWC’s team of technical experts engaged the Wildfire Resiliency Code Board via public comment to recommend these effective provisions.
In 2008, California adopted California Building Code Chapter 7A, Materials and Construction Methods for Exterior Wildfire Exposure. Under this code, redwood siding and decking are approved for use in California’s WUI fire hazard severity zones. Now approaching two decades in effect, this code has proven itself by reducing wildfire losses of new construction in California. In fact the Chapter 7A provisions have proven so effective that they have been incorporated into California’s new 2025 California Wildland-Urban Interface Code (CWUIC).
As of this date, the Colorado Wildfire Resiliency Code Board has not responded to letters of recommendation from the wood products industry to incorporate California’s successful WUI provisions. Despite AWC’s recommendations to utilize these proven methods, the Board proceeded with finalization of the CWRC without integration. As such the future for the use of natural wood decking and siding such as Redwood and Cedar remains in limbo.
Get Involved
As stakeholder in this industry, and as builders, designers and homeowners, you are encouraged to be heard and maintain your building options and reduce housing costs in Colorado. You can get involved by contacting your local state Senator and Representative in the Colorado State Legislature, and your local building department officials. You may also download, print, email, or forward a PDF copy of this information to other concerned stakeholders:
2025 Colorado Wildfire Resiliency Code: What it Means for Exterior Wood Construction
About the Mendocino Companies
The Mendocino Companies include Allweather Wood, Humboldt Redwood Company, Humboldt Sawmill Company, Mendocino Forest Products, Mendocino Redwood Company.
In aggregate, Mendocino Companies own nearly 450,000 acres of Forest Stewardship Council® (FSC® C013133) certificated timberland, constitutes the largest waterborne wood treater in the Western USA, and is the largest producer of redwood lumber in the world. Collectively providing over 900 employees and their families with excellent wages and benefits in rural communities of the Western USA. Additionally, Mendocino Companies own and operate a 25-megaWatt biomass cogeneration power plant and wood pellet plant, both in California.
For more information, please visit https://www.MendoCo.com/.
