Why Jefferson County and Clear Creek County Adopted New Wildfire Codes

Large parts of Jefferson County (the foothills communities around Golden, Evergreen, Morrison, and the mountain corridor west of Denver) and all of neighboring Clear Creek County (Idaho Springs, Georgetown, Empire, Silver Plume, and the Interstate 70 mountain corridor) sit directly in Colorado’s wildland-urban interface, where homes and neighborhoods meet fire-prone forest and grassland. Front Range and mountain-corridor wildfire risk has been rising for years, and building codes are one of the few tools a county has to make homes and neighborhoods more likely to survive a wildfire once one starts. Jefferson County’s WRC formalizes what many builders in these areas already treated as best practice, ignition-resistant materials and defensible landscaping, into an enforceable permitting requirement, and Clear Creek County has moved in the same direction for its own WUI areas.

A note on Evergreen: Evergreen isn’t entirely inside Jefferson County. The community straddles the Jefferson/Clear Creek county line, so which set of requirements applies (and who to call to confirm) depends on the specific address. HRTI always confirms the correct county before finalizing a project scope in this area.

Does the WRC Apply to Your Property?

The WRC only applies to unincorporated Jefferson County, not to homes inside city limits of Golden, Lakewood, Arvada, Wheat Ridge, or other incorporated municipalities, which have their own codes. Within unincorporated Jeffco, the code applies to properties inside the Wildland-Urban Interface (WUI) Overlay District, which the county divides into two risk classes:

●      Class 1 (lower hazard): “Perimeter” areas adjacent to wildland vegetation and “Interior” areas farther from it.

●      Class 2 (higher hazard): Wildland-urban intermix areas with moderate-to-high fire hazard, which carry additional defensible-space requirements.

The fastest way to check a specific address is the county’s interactive WUI Overlay District map, or by contacting Jefferson County Planning & Zoning directly at 303-271-8700. If your home is in the foothills or up against open space, it’s worth checking even if you’re not currently planning a project; the map also affects future resale and remodel plans.

Clear Creek County applies a comparable structure-hardening and defensible-space standard to homes in its own WUI areas, which cover most of the county given its mountain terrain. Clear Creek’s specific overlay boundaries, risk classes, and permit thresholds are set by county code rather than Jeffco’s, so don’t assume the details line up exactly; confirm your address and project scope with Clear Creek County Planning & Building at 303-679-2300 or through the county’s Permits page before finalizing materials.

What Actually Triggers Compliance

Inside the WUI Overlay District, the WRC applies to:

●      All new buildings

●      Building additions

●      Re-roofing

●      Re-siding

●      Deck replacement

●      Any exterior alteration affecting 25% or more of the building’s exterior surface area

It does not apply to:

●      Interior remodels (kitchens, bathrooms, basements) with no exterior work

●      Exterior work affecting less than 25% of surface area

●      Painting, staining, and general maintenance

●      Work on designated historic structures

●      Small detached accessory structures (under 120 sq. ft., one story, sited 10+ feet from other buildings)

●      Barns sited 50+ feet from occupiable structures

●      Fences sited 8+ feet from structures

In practice, this means a straightforward repaint is exempt, but a re-roof or a full re-side (exactly the kind of project HRTI handles every week) triggers the code if the home is inside the overlay district. These specific triggers and exemptions are Jefferson County’s; Clear Creek County’s thresholds are similar in spirit but should be confirmed with Clear Creek Planning & Building for a specific project.

Structure Hardening Requirements (Jefferson County WRC Chapter 4)

For covered projects, Jefferson County’s code requires ignition-resistant or noncombustible materials and details across the whole building envelope, including:

●      Roofing: Class A fire-rated roof covering

●      Gutters & downspouts: noncombustible materials, kept clear of debris

●      Attic, soffit, and foundation vents: 1/8-inch metal mesh screening to block ember intrusion

●      Exterior walls & siding: noncombustible or ignition-resistant materials

●      Flashing: noncombustible materials

●      Windows & doors: tempered or dual-pane glazing

●      Underfloor/crawlspace enclosures: noncombustible or ignition-resistant materials

●      Decks: noncombustible or ignition-resistant decking and framing

●      Fascia, eaves & soffits: noncombustible or ignition-resistant materials

●      Fencing & retaining walls within 8 ft of structures: noncombustible or ignition-resistant

materials: stone, masonry, concrete block, metal, or approved composites

Clear Creek County requires the same category of ignition-resistant, noncombustible building materials for covered projects in its WUI areas. HRTI specs materials to this same standard on Clear Creek jobs; ask your Clear Creek County building official to confirm any product-specific approval before ordering.

Defensible Space Requirements (Jefferson County WRC Chapter 5)

Separate from the building itself, Jefferson County’s WRC also sets landscaping and vegetation-management rules in three zones measured out from your structures. Zone 3 only applies in the higher-hazard Class 2 areas. Clear Creek County likewise expects defensible-space vegetation management around structures in its WUI areas; the exact zone distances and prohibited-plant lists should be confirmed with Clear Creek County directly rather than assumed to match Jeffco’s table below.

How This Gets Permitted and Inspected

Structure hardening (roofing, siding, windows, decks, etc.) is reviewed by the Building Safety Division as part of your standard building, siding, or roofing permit; there’s no separate fee beyond the normal Building Permit Fee Schedule.

Defensible space is handled separately: the property owner hires a county-approved Wildfire Mitigation Specialist, who inspects the property, the owner (or contractor) does the required vegetation work, and the specialist signs off with a final inspection. There’s no county fee for this permit. For re-siding projects specifically, homeowners have the option to self-certify Zone 1 (0–5 ft) compliance using the county’s provided form instead of hiring a specialist for that portion. This permitting and inspection process is Jefferson County’s; Clear Creek County administers its own permitting through its Planning & Building department, so a Clear Creek project should be scoped with that office directly.

How HRTI Helps You Stay Compliant

If your project is inside the WUI Overlay District, the materials you choose aren’t just a style decision anymore: they need to meet the WRC’s structure hardening standards. HRTI already installs several product lines that fit these requirements:

Roofing: including CeDUR synthetic shake, which carries a Class A fire rating and Class 4 impact resistance, alongside our other Class A-capable roofing systems

Siding: James Hardie fiber cement and LP SmartSide are both widely recognized as noncombustible / ignition-resistant siding choices for WUI construction, and Class A fire-retardant-treated real wood siding is available for homeowners who want a natural wood look (see below)

Windows & Doors: dual-pane, Low-E glazing is already standard on the lines we install

Painting: exempt from the WRC on its own, but our prep process catches the rotted trim and damaged substrate issues that matter for a compliant re-side down the line

If you’re in Golden, Evergreen, Morrison, Idaho Springs, Georgetown, or anywhere else in the Jefferson County or Clear Creek County foothills and mountain corridor, and you’re planning a re-roof, re-side, addition, or deck replacement, it’s worth a call before materials are chosen, not after a permit gets flagged.

Want Real Wood Siding in the WUI? Class A Fire-Rated Options Exist

Raw, untreated wood siding doesn’t meet the WRC’s noncombustible or ignition-resistant standard on its own, but that doesn’t mean a natural wood look is off the table inside the WUI Overlay District. Real wood can meet an ignition-resistant standard when it’s pressure treated with an exterior-grade fire retardant and tested to a Class A flame-spread rating, the same 0 to 25 flame-spread index under ASTM E84 used to rate Class A roofing.

Achieving that rating in real wood isn’t a stain or a surface coating. It takes a pressure-impregnated treatment that drives fire-retardant chemicals into the wood’s cell structure so it chars instead of sustaining flame. For an exterior product, that treatment also has to be formulated so it won’t leach out in rain and snow the way older interior-grade fire retardants could; a treatment that needs to be reapplied every few years isn’t a realistic long-term fix for a house.

Several different manufacturers offer this kind of Class A fire-retardant-treated real wood. Montana Timber Products, a supplier HRTI has worked with before, treats its ranchwood, AquaFir, and Charwood siding lines with a proprietary process called Fireline: Class A fire rated and WUI compliant, pressure treated with an all-natural, non-toxic formulation the company says lasts the lifetime of the wood with no retreatment needed. The Cedar Shake & Shingle Bureau offers a similar path through its Certi-Guard certification, which designates independently fire-retardant-treated cedar shakes and shingles for jurisdictions that require that protection. Both are examples of the same underlying idea: real wood, properly treated, can be engineered to meet a Class A standard rather than just marketed as one.

Because treatment certifications and code acceptance vary by manufacturer and by jurisdiction, confirm with Jefferson County Building Safety or Clear Creek County Planning & Building, whichever applies to your address, that a specific Class A fire-retardant-treated wood product satisfies the local ignition-resistant siding requirement for your project before materials are ordered. HRTI can help spec a compliant, treated real-wood product alongside fiber cement, engineered wood, or metal siding options.

A Note on Cost: Tax Credits and Grants Can Help

Wildfire mitigation work isn’t only a cost center. Colorado offers an income tax deduction/credit for qualifying wildfire mitigation measures, and the Colorado State Forest Service runs a Forest Restoration and Wildfire Risk Mitigation Grant Program that homeowners and communities can apply to. Ask your tax professional whether your specific project qualifies, and see the sources below for links to both programs.

Frequently Asked Questions

When did the Jefferson County Wildfire Resiliency Code take effect?

The Jefferson County Board of County Commissioners approved the WRC on March 10, 2026, and it became effective July 1, 2026.

Does Clear Creek County have a similar wildfire code?

Yes. Clear Creek County applies a comparable structure-hardening and defensible-space standard to homes in its own wildland-urban interface areas, which cover most of the county given its mountain terrain. The specific overlay boundaries, permit thresholds, and code sections are set by Clear Creek County rather than Jefferson County’s WRC, so confirm the details for a specific address with Clear Creek County Planning & Building at 303-679-2300.

Does the WRC apply to homes in Golden or Evergreen?

It depends on whether the property is inside city limits or in unincorporated Jefferson County, and whether it falls within the WUI Overlay District. The town of Golden has its own municipal boundary; many surrounding foothills areas, including large parts of Morrison, are unincorporated Jefferson County and likely to fall in the overlay. Evergreen is split between Jefferson County and Clear Creek County, so an Evergreen address may fall under either county’s requirements. Check the county’s interactive map or call Planning & Zoning (Jefferson County) or Planning & Building (Clear Creek County) to confirm a specific address.

My project is just a re-roof. Does that really require a wildfire permit?

If the home is in the WUI Overlay District, yes: re-roofing is specifically listed as a triggering exterior alteration, and it must use a Class A fire-rated roof covering. The review happens through your standard roofing permit with Building Safety, not a separate process.

Can I do a partial re-side and stay under the code?

The code exempts exterior work affecting less than 25% of the building’s surface area. A small patch repair may fall under that threshold, but a full or majority re-side will not. Your contractor and the Building Safety Division can help confirm where a specific project falls.

What happens if I don’t comply?

Structure hardening compliance is enforced through the standard building permit and inspection process: work that doesn’t meet code requirements won’t pass inspection or receive final sign-off. For defensible space, a Wildfire Mitigation Specialist has to sign off on the work. Non-compliance can hold up a permit, a certificate of occupancy, or a project closeout.

Are there fees for these permits?

Structure hardening review is included in your standard Building Permit Fee Schedule cost, with no separate fee. Defensible space permits carry no additional county fee, though homeowners typically pay the Wildfire Mitigation Specialist directly for their inspection and work.

Can I still get real wood siding if my home is in the WUI Overlay District?

Possibly, if it’s treated. Untreated wood siding doesn’t meet the ignition-resistant standard in either county, but pressure-treated, Class A fire-rated real wood products, like Montana Timber Products’ Fireline-treated siding, are built specifically to meet ignition-resistant requirements while keeping a natural wood appearance. Confirm the specific product’s code acceptance with Jefferson County Building Safety or Clear Creek County Planning & Building before ordering materials.

HRTI: Windows, Doors, Siding, Painting & Roofing, Done Right, From the Studs Out

HRTI has been a full-service exterior remodeling contractor in the Denver metro area and foothills since 1972. Whatever brought you to this page (a siding repair, a re-roof, new windows, or an exterior paint job), our crews inspect what’s behind the surface (sheathing, flashing, moisture barriers, framing) before we ever touch the finish material, because the finish is only as good as what it’s fastened to.

We install and service:

Windows & Doors: energy-efficient replacement windows and entry/patio doors from Pella, Sierra Pacific, Simonton, Sunrise, Weathershield, and more

Siding: James Hardie fiber cement, LP SmartSide (including Diamond Kote® and RigidStack®), vinyl, metal, and specialty wood siding, installed over the correct sheathing every time

Exterior Painting: full prep, repair of rotted or damaged substrate, and premium Sherwin-Williams coatings

Roofing: asphalt, synthetic, stone-coated steel, and Class A fire-rated options like CeDUR synthetic shake

Have questions about your specific project, a job another contractor started, or whether your home is up to current code? Call HRTI at 303-984-6159 or email info@hrti.com for a free consultation. You can also reach us anytime through our contact page.