The 2025 Colorado Wildfire Resiliency Code took effect in Routt County on 1 July 2026, and every building permit application received on or after that date falls under it. Routt County adopted a local map that classifies the entire county as Moderate or High fire intensity, so the stricter Class 2 requirements apply everywhere the building department has jurisdiction, including inside Steamboat Springs city limits. Buying an existing house does not trigger the code, but replacing a quarter of the roof, replacing a quarter of the exterior walls, or adding 500 square feet or more does.

I have had this conversation at a dozen kitchen tables since July. Buyers hear “new wildfire code” and picture a bill arriving for a house they have not closed on yet. Builders hear it and start guessing at numbers. Both reactions come from the same place, which is that the code is real and specific and almost nobody has read it. So I did. What follows comes from the adopted code text and the signed policy published by the Routt County Regional Building Department, the state code text published by the Colorado Division of Fire Prevention and Control, the Colorado Division of Insurance, and the Colorado Office of the State Auditor. Where a claim in circulation did not survive checking, I have said so rather than repeat it.

What is the Colorado Wildfire Resiliency Code?

It is a statewide model code for building in wildfire country. The Colorado General Assembly created the Wildfire Resiliency Code Board through Senate Bill 23-166 in 2023 and directed it to set a minimum standard for two things: hardening the structure against embers and flame, and managing the vegetation immediately around it. Local governing bodies in the wildland-urban interface then adopt and enforce it, and may go beyond the state minimum.

The sequence of deadlines matters, because a loose version of it circulates locally. Per the Colorado Office of the State Auditor’s June 2026 evaluation, local governing bodies in the wildland-urban interface were required to adopt code standards by 1 April 2026, with enforcement beginning by 1 July 2026. The Routt County Regional Building Department’s own presentation states the same adoption deadline, that 1 April 2026 was the deadline to have the 2025 Colorado Wildfire Resiliency Code adopted and signed by all Routt County jurisdictions. Every jurisdiction here met it.

Chapter 1 contains the rules that decide whether your project is caught at all. Chapter 3 is mapping and applicability. Chapter 4 is structure hardening, meaning roofs, vents, walls, eaves, decks, windows and doors. Chapter 5 is site and area requirements, meaning vegetation, fencing and retaining walls. In Routt County the building department administers Chapter 4, and the planning departments and fire districts administer Chapter 5.

When did it take effect here, and which permits does it catch?

The Routt County Regional Building Department set 1 July 2026 as the effective date. Its signed adoption policy, dated 14 May 2026, states that all permit applications applied for and received through the CityView portal on or after that date fall subject to the code, and that all documents and plans must be designed in accordance with the code as written or the application will be deemed incomplete. That last clause matters more than the date. The department is not accepting an application and then negotiating wildfire compliance during review. Plans that do not show compliance are rejected as incomplete. Build that into your schedule.

The same date applies across everywhere the department serves: unincorporated Routt County, the City of Steamboat Springs, and the towns of Hayden, Oak Creek and Yampa.

Does my part of Steamboat Springs fall under the code?

Yes, and this is the most misunderstood point of the lot. People keep telling me there must be a low intensity or unclassified pocket somewhere that gets a pass. Here is how the mapping actually works.

The statewide code sets three fire intensity classifications, Low, Moderate and High, at Section 303.2. Under Section 303.1.2 the authority having jurisdiction may develop and adopt its own local map instead of using the state map, and the Division of Fire Prevention and Control confirms that governing bodies may develop a local map to use as a supplement to or as an alternative to the state map, subject to review by the Wildfire Resiliency Code Board. Routt County took that route and adopted a local map.

The adopted local map, published as Appendix A to the code, has four fire intensity entries in its legend: High Intensity Non-Federal, High Intensity Federal, Moderate Intensity Non-Federal and Moderate Intensity Federal. There is no Low category and no unclassified category on the Routt County map. The building department’s own summary states that the amended adopted wildfire map classifies all areas of Routt County as Moderate or High intensity, that Class 2 requirements therefore apply county wide, and that no exceptions are offered to change the map. The adopted code text for the City of Steamboat Springs says the same in its Section 301.2, adopting the county map as identifying all of the city within the Moderate or High Fire Intensity Classification.

It is worth being precise about what a Low classification would have meant, because it is not an exemption. Under Section 303.3 of the state code, parcels identified as Low fire intensity must still be constructed and maintained to Class 1 structure hardening and Class 1 site and area requirements. Low is a lighter tier, not an escape from the code. The practical difference here is that Routt County has no Low tier, so every regulated project sits in Class 2, which includes all of the Class 1 requirements plus more.

I am buying an existing house. Does this change anything for me?

Buying does not trigger the code. There is no wildfire inspection at closing, no certificate to obtain, and no obligation created by the transfer of title. Section 101.4 applies the code to conditions arising after adoption, and Section 102.8 lets a legal existing use continue. The building department’s commentary is blunt about it: the code does not apply to pre-existing site and area conditions on sites that had buildings on them before the effective date, provided those buildings were properly permitted. What changes is the cost and scope of future work.

Work you are planning	What the code requires	Section
Addition increasing the footprint by 500 square feet or more	The addition must conform to what is required for a new building. The existing house is not pulled in unless another trigger is also met	101.5
Addition of 499 square feet or less	Not subject to the code on its own, under either Chapter 4 or Chapter 5	102.10
Roof work affecting 25 percent or more of the roof surface	The entire roof covering must be replaced to the new construction standard, a Class A covering or assembly	101.6
Siding work affecting 25 percent or more of total exterior wall surface	The entire exterior wall surface, including attachments, must meet the new construction standard, and the zone within 5 feet of the structure must be brought into compliance	101.7
Window and door replacement	Treated as interior alteration and exempt, unless the total replacement area exceeds 25 percent of all exterior wall surfaces	102.10

Source: 2025 Colorado Wildfire Resiliency Code as adopted and published by the Routt County Regional Building Department, Chapter 1, read against the state code text published by the Colorado Division of Fire Prevention and Control. Accessed August 2026.

Two of those catch people out. The 25 percent roof trigger requires the whole roof to come up to standard, not the 25 percent you touched. And the exterior wall trigger pulls Chapter 5 along with it, so a re-siding project becomes a landscaping project within 5 feet of every exterior wall of the existing building. The department’s own example is a tree canopy reaching into that 5 foot zone, which would then have to be pruned.

If you are buying an older house with the intention of re-siding it, price that properly. It is now something I raise before an offer goes in rather than after inspection. My out-of-area buyer’s guide covers the rest of the inspection and contract path.

What work is exempt?

Section 102.10 lists work for which compliance is not required: interior alterations, additions not increasing the footprint by more than 500 square feet, exterior wall work affecting less than 25 percent of all exterior walls, roof covering work affecting less than 25 percent of the roof, other exterior alterations affecting less than 25 percent of the exterior, painting and staining and similar maintenance, one-storey detached non-habitable structures of 120 square feet or less standing at least 10 feet from the nearest occupiable structure, accessory Group U buildings including agricultural structures more than 50 feet from occupiable space, fences more than 8 feet from a habitable structure, and any 35 acre parcel with only one residential structure on it that does not abut a residential or commercial area.

Two special cases sit outside that list. Buildings designated historic under a federal, state or local preservation programme are subject only to Class 1 structure hardening under Section 403, which still covers roof covering, gutters and downspouts and ventilation openings, and the department states they are not subject to Chapter 5 for existing landscaping. Homes built to the federal HUD manufactured housing standards are exempt from structure hardening on their first installation, but a HUD home moved into the jurisdiction is subject to the code.

I am building new. What changes at permit time?

Three things, and only one of them is about materials. The plans must state the code editions the project was designed under, naming the 2025 Colorado Wildfire Resiliency Code alongside the building and energy codes. The architectural set must carry building, wall and assembly section cuts of the exterior that show compliance, so the reviewer can see the eave, fascia, wall assembly, roofing and decking without guessing. And the application must include a Wildfire Site Plan, uploaded separately from the ordinary site and utility plan.

That site plan is not a sketch. The department asks for dashed lines at 5 and 10 feet from the building, and on larger lots at 30 and 100 feet, with existing and proposed trees, shrubs, dead material and fuel accumulations shown, along with spacing between trees and between shrubs and trees. Tree canopies must be drawn, not just trunk centres. Any plant kept in the immediate zone is named against the Colorado State Forest Service ignition-resistant plant list.

Element	Class 2 requirement	Section
Roof, gutters and downspouts	Class A covering or assembly tested to ASTM E108 or UL 790, profiled coverings firestopped at the eave, valley flashing over cap sheet underlayment, and noncombustible gutters and downspouts	403.2, 403.3
Ventilation openings	The code sets a performance path, listed vents tested to ASTM E2886, and a prescriptive path, noncombustible corrosion-resistant mesh with openings not exceeding one eighth of an inch. The building department’s published note states that in addition, all ventilation openings must meet the standards in Section 403.4.1. Confirm which path the department will accept before ordering vents	403.4, 403.4.1, 403.4.2
Eaves, soffits and fascia	Protected by noncombustible or ignition-resistant material, a one hour rated assembly, five eighths inch Type X drywall, or nominal two inch lumber	404.2
Exterior walls	A one hour assembly rated from the exterior side, noncombustible material, heavy timber or log construction, fire-retardant-treated wood, or ignition-resistant material, plus 6 inches of flashing at ground, deck and roof intersections	404.3
Decks	Walking surface of noncombustible material, Class A rated material, fire-retardant-treated wood or ignition-resistant material. Composite decking accepted at a minimum Class B rating	404.5
Windows, skylights and doors	Glazing tempered, multilayered, glass block or rated at 20 minutes. Doors noncombustible, solid core wood at least one and three quarter inches thick, or rated at 20 minutes	404.7, 404.8
Garage doors	Perimeter gaps at head, sill and jamb limited to one eighth of an inch, controlled by tested weather-stripping, door overlaps or metal flashing	404.9
Detached accessory structures within 50 feet of the house	Exterior walls built to the same standard as the house	404.10

Source: 2025 Colorado Wildfire Resiliency Code, Chapter 4 Class 2 structure hardening, state code text published by the Colorado Division of Fire Prevention and Control, read against the code as adopted and published by the Routt County Regional Building Department. Accessed August 2026.

What does the code require in the yard?

Chapter 5 divides the ground around the building into three ignition zones. Because Routt County is mapped Class 2, all three apply to new construction and to additions of 500 square feet or more, though for an addition only the part of the site the addition encroaches on is measured. Class 2 includes every Class 1 requirement and then adds to it, so read the zones cumulatively rather than as alternatives.

Zone	What is required	Section
Zone 1, immediate, 0 to 5 feet	Noncombustible hard surfaces such as rock, gravel, sand, concrete, bare earth or stone and concrete pavers. All plantings removed, including shrubs, slash and combustible mulch, except ignition-resistant vegetation from a list approved by the authority having jurisdiction that is not less than the Colorado State Forest Service list. No new trees planted. Mature trees of at least 10 inch diameter, measured 4.5 feet above ground level, may be maintained. Tree crowns reaching within 10 feet of a structure pruned to keep a minimum 10 foot clearance. Branches pruned to a height of 6 to 10 feet from the ground, or a third of the total height of the tree, whichever is less	502.1.2, 502.1.3, 502.1.4
Zone 2, intermediate, 5 to 30 feet	Hazardous dead plant material removed from live vegetation. No large accumulations of surface fuels such as logs, branches, slash and combustible mulch. Tree crowns reaching within 10 feet of a structure pruned to keep a minimum 10 foot clearance, and branches pruned to a height of 6 to 10 feet from the ground, or a third of the total height of the tree, whichever is less. Tree crowns spaced to prevent structure ignition and promote fuel discontinuity. Shrub groups spaced to prevent structure ignition and kept at least 10 feet from the edge of tree branches	503.2.2 to 503.2.5
Zone 3, expanded, 30 to 100 feet	Tree crowns spaced at a minimum of 6 to 10 feet. That spacing is the only requirement the expanded zone carries. The branch pruning rule belongs to Zones 1 and 2, not to this zone	503.3.2

Source: 2025 Colorado Wildfire Resiliency Code, Chapter 5 Sections 502 and 503, state code text published by the Colorado Division of Fire Prevention and Control, read against the Routt County Wildfire Resiliency Site Plan Requirements published by the Routt County Regional Building Department. Accessed August 2026.

If you are pricing a 100 foot mitigation scope, note what Zone 3 does and does not ask for. It asks for crown spacing. It does not carry the ladder-fuel pruning requirement that applies close to the house. Getting that the wrong way round is the difference between a quote for spacing work across the outer ring and a quote for limbing every tree on it.

Two site items are easy to forget in a landscape budget. Retaining walls must be noncombustible or ignition-resistant where they sit within 8 feet of a regulated structure, where they support one, or where they are integral to getting from the building to a public way, easement or private road. Fencing within 8 feet of a regulated structure must also be noncombustible or ignition-resistant, with an exception allowing vinyl. Address markers and road signage must be posted and kept clear.

Was there a deadline for applications filed before the effective date?

Yes, and it is worth stating precisely because a loose version is circulating. The department published a signed exemption policy on 14 May 2026. Applications received before 1 July 2026 are exempt only if they satisfy all five of these conditions.

The fifth condition is the one that will bite between now and the end of the year. A project that squeaked its application in during June but is still in plan review in late December does not stay exempt by virtue of having applied early. It has to be issued. If you are buying a lot with an in-flight permit, or a house from a seller who is mid-permit, ask for the application date, the review status and the projected issuance date, then confirm all three with the building department rather than taking anyone’s word for it.

What the code does not do

It does not set your insurance premium, and the state is explicit that the map is not an insurance tool. The Colorado Division of Insurance publishes that the map created by the Wildfire Resiliency Code Board is for the application of the 2025 Colorado Wildfire Resiliency Code only, that it is not intended for insurance purposes, and that insurance companies use their own tools, methodologies and maps to assess risk and make decisions about where to offer insurance and how much to charge for coverage. Asked directly whether the map will impact the cost or availability of homeowners insurance, whether insurers can use it to cancel in high risk areas, and whether a high risk designation on it will impact rates, the Division answers no to each, and each time gives the same reason: insurers rely on their own, more granular maps and methodologies for premium rates, eligibility for new policies and renewals, and Colorado law requires insurers to evaluate coverage using multiple factors and rates to be actuarially sound.

Read that for what it says. It is an answer about the map, not a promise about your premium. On whether the new code will lower your costs, the Division does not claim it will. Its published answer is to talk to your agent about the mitigation and home hardening discounts available on your policy, and to talk to your agent about how your coverage extends to new and updated building code requirements. That second one is worth a phone call if you own here, because rebuilding to this code after a loss costs more than rebuilding to the old one. I have seen premium impact figures attributed to analysts and aggregators. I am not publishing any of them, because none come from the state and none describe your house. For your own policy, speak to your insurance agent or contact the Division of Insurance directly.

The code also does not force existing homeowners to re-side, re-roof or re-landscape on a schedule. There is no compliance date for a house that already stands and is not being worked on. And it does not replace the fire restrictions and mitigation guidance you may already follow. It sits alongside them as a permitting requirement.

What does compliance cost?

No Routt County figure for the added cost of building to this code is published, and I am not going to invent one. What I can give you is the list of line items that change, so you can get a real quote against a real scope rather than a percentage someone guessed at: cladding, soffit and fascia specification; vents, which move to listed ember-resistant products or one eighth inch mesh, and which you should price only after the building official has confirmed which path applies; decking surface, plus the full structure of any covered or stacked deck; glazing; gutters, downspouts, garage door sealing and flashing details; landscape work in the first 5 feet, crown spacing further out, and fencing and retaining wall materials within 8 feet; and design fees for the Wildfire Site Plan and the extra assembly section cuts.

On the vegetation side there is a public cost reference. In its June 2026 evaluation of the state wildfire mitigation tax credit, the Colorado Office of the State Auditor cited Colorado State Forest Service data putting a one acre defensible space project around a home at roughly $3,200 to $6,100 in total. That is mitigation work rather than construction, but it is state-sourced rather than a guess.

There is also a Colorado income tax credit for wildfire mitigation measures at Section 39-22-543 of the Colorado Revised Statutes. Per the same evaluation, for tax year 2026 the credit equals 100 percent of eligible mitigation expenses up to a maximum credit of $1,000, it is subject to an income limitation the Department of Revenue adjusts annually for inflation, and the work must be performed by a third-party service provider. For anyone reading this as a construction subsidy, note that the auditor states the credit cannot be claimed for structural mitigation such as installing a fire-resistant roof, because the statute does not cover home hardening. I am a real estate broker, not a tax adviser or an attorney. Confirm anything in this section with a Colorado tax professional or a Colorado attorney before relying on it for your own return or your own contract. For the wider picture on carrying a home here, see my guide to the cost of living in Steamboat Springs.

How to confirm this for your own property

Every date, threshold and exemption above comes from documents the building department and the state publish, but code administration involves interpretation and policies change. For a specific parcel or scope of work, go to the source.

Ask four questions. Does my scope of work trigger the code. If it does, what does the department expect on the Wildfire Site Plan for a lot like mine. Which ventilation path will you accept. And if there is an existing application on the property, what is its status against the 31 December 2026 issuance deadline.

Frequently Asked Questions