2025 Colorado Wildfire Resiliency Code

Introduction

The Colorado Wildfire Resiliency Code (CWRC) is a state-mandated code update that established regulations for construction and property maintenance in Wildland-Urban Interface (WUI) areas. The goal is to help safeguard life and property from wildfire risks.

The CWRC introduces two classes of structure hardening (Class 1 and Class 2) based on fire intensity classification (low, moderate and high), and outlines requirements for building materials, defensible space and site features. Like other building codes, the CWRC allows the City to enforce, permit, inspect and consider appeals of the standards. Unlike many traditional building codes, the CWRC also establishes ongoing maintenance requirements related to exterior site conditions and wildfire mitigation features.

View the Colorado Wildfire Resiliency Code


Overview

Created in June 2025, the CWRC will be effective in the City of Centennial on June 30, 2026. The CWRC is a comprehensive set of regulations intended to enhance life safety and property protection in Colorado's WUI areas. The primary purpose of the code is to reduce wildfire risk by helping prevent fires from spreading to structures and preventing structure fires from spreading to wildland fuels. The CWRC supplements existing building and fire codes and uses a tiered approach, meaning requirements vary based on the level of wildfire hazard present in a specific area. The code also extends beyond traditional building code requirements by addressing site-hardening measures around structures, including defensible space and other improvements intended to reduce wildfire risk on a property, not just within the building itself.

Where does it apply?

The CWRC applies to areas where homes, buildings and other developments are located near or among natural vegetation and wildland fuels. The Colorado Wildfire Resiliency Board (CWRCB) adopted a statewide that defines fire intensity areas based on factors such as vegetation, topography, weather patterns and fire behavior modeling. Areas are classified as Low, Moderate and High Fire Intensity, which determine the applicable code requirements. Within Centennial, areas are currently classified as Low (yellow) and Moderate (orange) Fire Intensity.

Colorado Wildfire Resiliency State Map

Use the Colorado Wildfire Resiliency Map to determine whether a property is located within a designated wildfire intensity area.

View the Colorado Wildfire Resiliency Map

Fire Intensity Zones

  • Low (Yellow) Zones: Areas with lighter fuel loads, gentler slopes and lower expected fire intensity
  • Moderate (Orange) Zones: Areas with moderate to heavy fuel loads, steeper terrain and higher expected fire intensity
  • High (Red) Zones: Areas with the highest expected fire intensity (NOTE: Centennial currently has no High zones) 

What does it mean for residents and businesses?

Centennial’s WUI regulations apply to the construction and alteration of structures with occupiable or habitable space, as well as defensible space requirements within designated fire hazard areas. The goal is to safeguard life and property from wildfire intrusion and reduce the risk of structure fires from spreading to wildland fuels.

When does it apply?

The CWRC requirements apply to: 

  • New residential and commercial construction
  • Defensible space around structures
  • Significant alterations, additions, and/or repairs
  • Projects involving 500 square feet or more added to a structure footprint
  • Projects affecting 25% or more of a structure’s exterior
  • Roof replacements when 25% or more of the surface area is replaced

When does it NOT apply?

The CWRC does not apply to: 

  • Interior alterations of existing structures
  • Parcels of 35-acres or more with one residential structure NOT abutting residential or commercial area
  • Exterior painting, staining and similar routine maintenance
  • Certain historic structures, where variances may be granted to preserve historic character

Frequently Asked Questions

Will this apply to my property?

Yes, the CWRC will apply if your property is located in a Low (Yellow) or Moderate (Orange) Zone on the 2025 Wildfire Resiliency Code State Map.

Residents can review whether their property is included by viewing Centennial’s CWRC mapped properties, which are based on the 2025 Colorado Wildfire Resiliency Code State Map.


How was the State Map created?

The State of Colorado, through the Division of Fire Prevention and Control and the Colorado State Forest Service, created the map and proposed model code at the direction of CWRCB. The Wildfire Resiliency Code State Map categorizes areas throughout Colorado using a Fire Intensity Scale based on three factors:

  • Vegetation types and fuel loads
  • Topography (slopes, terrain features)
  • Typical weather conditions

According to section 4.2 of the State’s WUI regulations, the original wildfire intensity layer was created at a highly detailed generated at a 20-meter resolution, then refined through smoothing, filtering and aggregation techniques to support statewide planning and implementation.”

Questions regarding the map creation and why certain areas are included should be directed to the Colorado WRCB. Centennial did not create this map, and was not involved in its development.

The map reflects potential wildfire intensity (how severely a fire could burn), not the likelihood of a fire starting.

The CWRC allows Centennial to evaluate site-specific conditions during permitting and review processes where local conditions may differ from the broader statewide analysis. Examples may include existing vegetation, topography, irrigation, development patterns or other physical characteristics) that differ from the generalized model. 


Does the CWRC require me to make changes to my property by a specific date?

No. Existing buildings approved before the code adoption may continue their current use without modifications. Existing landscaping may also remain as is unless future redevelopment or qualifying additions trigger application to the code.

Existing landscaping would only need to comply with the WUI Code requirements if a site is redeveloped with a new home or expanded by more than 500 square feet.


What are the building requirements that will apply to new construction?

Low (Yellow) Zones

New construction and expansions greater than 500 feet would require:

  • Class A roofing materials (asphalt, shingles, tile)
  • Non-combustible gutters
  • Ember-resistant roof and foundation vents

Moderate (Orange) Zones

Moderate zone requirements include all Low Zone requirements, plus:

  • One-hour fire-rated exterior wall assemblies
  • Non-combustible or fire-retardant treated exterior wall materials
  • Non-combustible or approved deck materials
  • Solid core, non-combustible or 20-minute fire-rated roofs
  • Ember-resistant garage door sealing

What landscaping and fencing requirements apply? Is there a complete ban on planting new trees?

No, trees are still encouraged to be planted, with a preference for thoughtful placement and increased use of deciduous species in WUI zones.

Landscaping requirements apply ONLY when constructing a new building or expanding a building by more than 500 square feet. In these instances, the following apply under the State WUI Code:

Low (Yellow) Zones

0-5 feet from structures:

  • Use non-combustible materials (rock, gravel, concrete) OR approved fire-resistant plants
  • No new trees within this zone
  • Non-combustible fencing within 8 feet of structure (vinyl is allowed)

Moderate (Orange) Zones

0-5 feet from structures:

  • Same as Low (Yellow) Zones

5-30 feet from structures:

  • Remove dead vegetation
  • Maintain spacing between trees and shrubs
  • Use rock mulch instead of bark mulch

30-100 feet from structures:

  • Maintain tree crown spacing to reduce fire spread

What does this mean for future development?

Many of the properties within the mapped CWRC area are already developed. In most cases, existing landscaping and building materials may remain unless future construction, additions, remodels or redevelopment trigger application of the code.

Over time, redevelopment and new construction may gradually incorporate additional wildfire resiliency measures.

Some wildfire mitigation strategies may align with existing Colorado trends toward drought-tolerant and waterwise landscaping, while also incorporating additional considerations related to vegetation spacing and combustible materials.

Potential long-term trends could include:

  • Reduced use of highly combustible vegetation near structures
  • Greater spacing between trees and shrubs near buildings
  • Increased use of non-combustible materials, such as rock mulch instead of bark mulch near structures
  • Continued use of drought-tolerant and native landscaping with wildfire considerations
  • Building materials and design features intended to improve wildfire resistance

Wildfire-resilient landscaping does not mean removing all trees or vegetation. The focus is on reducing combustible materials near structures and improving a property’s ability to better withstand wildfire exposure


How does this relate to other state-mandated codes?

The CWRC follows a similar legislative model used for other state-mandated construction codes, such as the Colorado Model Electric Ready and Solar Ready Code.

The State establishes minimum standards to address statewide concerns, while local jurisdictions remain responsible for adoption, enforcement and potential local amendments.


When will the code be adopted and enforced?

The code is adopted and will be effective June 30, 2026.


If this CWRC is approved by the State, how can I appeal it?

Under the state regulations, only governing bodies (like the Centennial City Council) may make petitions and appeals to the State Board for code modifications or map changes. Individual residents cannot directly petition the State Board. Citizens' requests for individual code modifications must be made to their local governing body, which can then petition the State Board on their behalf.


Can Centennial request modifications to the WUI Code or map?

Yes. Centennial may petition the State Board for modifications may also develop its own local map using independent analysis and field inspections, subject to State Board approval.

At this time, Centennial has not identified specific modification it intends to pursue.


Would an Accessory Dwelling Unit (ADU) need to comply with the CWRC requirements?

Yes. A standalone ADU would need to comply because it is a habitable space. Attached ADUs would need to comply if the addition exceeds 500 square feet to an existing building.


If an owner replaces a roof, will other parts of my property be inspected??

No. Roof replacement permits would only require compliance with applicable roofing requirements including Class A roofing materials and non-combustible gutters or downspouts.


Do owners need to replace siding if windows are replaced?

No. Existing siding will not need to be replaced as part of a window replacement project. 


Does a shed need to comply with WUI requirements for building materials?

No, provided the shed is located more than 8 feet from a habitable structure. 


Will existing fences need to be replaced?

No. Only new fencing within 8 feet of a structure would need to comply with non-combustible or vinyl fencing requirements.


Does an owner have to tear down a deck and replace it with non-combustible materials?

No. Deck requirements only apply when constructing a new deck or altering a deck through a permitted project. 


How can I stay updated on CWRC Code for Centennial?