Most Front Range cities met a wildfire building code for the first time in July 2026. Boulder is on its third. The city first adopted the International Wildland-Urban Interface Code in 2014, has revised it on a six-year cycle since, and put the 2024 edition with local amendments into force on August 1, 2025, eleven months ahead of the state deadline.
GS Exterior Experts has worked under all three versions, and this page covers the current one as the city applies it: which class your property falls in, which elements each permit touches, and which products clear plan review without a second round of comments.
Boulder adopted the 2024 International Wildland-Urban Interface Code as the basis for its 2025 Wildfire Resiliency Code through Ordinance 8695 in June 2025, including its own amendments and map. This means Boulder homeowners follow the city’s code, which meets or exceeds state requirements and has been in place through two previous editions.
In the 2025 update, the mapped WUI Area expanded, meaning some streets previously outside the boundary may now be included. More exterior work now requires permit review for material checks. However, the structure remains the same, with three classes of ignition-resistant construction based on fire-hazard severity, which apply only to permitted elements.
Boulder's map assigns every WUI Area parcel to one of three ignition-resistant construction classes, and the city applies the code only to the work on the permit. Between them, those two facts answer most of the questions we hear.
Class 1, the highest hazard tier, reaches the roof, walls, vents, underfloor space, decks, glazing, and exterior doors; walls must be noncombustible or ignition-resistant and roofs Class A. Class 2 keeps the Class A roof and protected walls but opens more material options at decks and projections. Class 3, where many newly mapped parcels land, requires only a Class B roof and mesh-screened vents, with no wall rule at all.
The city says the requirements apply when a permit is issued and are limited to the proposed scope. Its own example is a deck permit, which triggers only the deck rules. A re-roof brings the roof assembly rules and nothing about walls; a siding permit brings the wall covering and flashing details and nothing about the roof. Fuel modification applies only to new construction, so a re-roof never sends a crew into your yard.
Any new fence or gate section within 8 feet of a structure in the WUI Area must be noncombustible; beyond 8 feet, wood is fine. Fences under 7 feet need no permit, so the rule bites when a permit is in play. The usual fix is a short metal or masonry section at the wall, not a new fence.
Boulder reviewers see the same product submittals often, and a listing they recognize moves faster than one they have to research. These are the systems we submit most, trade by trade.
A Class A roof assembly satisfies Class 1 and Class 2 and exceeds Class 3. Standing seam metal, stone-coated steel panels, and Class A synthetic shingles are our three standard submittals, each carrying the ASTM E108 or UL 790 listing the reviewer wants, and each also carries the Class 4 impact rating that matters on a Boulder roof for hail. All three are part of the roofing systems we install in Boulder.
For Class 1 and Class 2 parcels, James Hardie fiber cement, which carries an ASTM E136 noncombustible rating, is the wall covering we submit by default. For a Class 3 parcel or a homeowner who wants a different look, our siding installation service covers other noncombustible and ignition-resistant claddings, with a listing for each.
On Class 1 and Class 2 parcels, our deck replacement and new deck construction frames in steel under a Class A or ignition-resistant surface, with the underside treated as part of the scope. Ember-resistant vents tested to ASTM E2886 satisfy every class and are the cheapest item on the list. A noncombustible fence section inside the 8-foot line is a small metalwork job we fold into the contract.
Class 1 and Class 2 require exterior glazing that is multilayered, tempered, or rated, and most modern double-pane units already qualify. We confirm the listing for each unit against your class before ordering, which is the step that keeps replacement windows from stalling a permit.
A Boulder wildfire-code project runs in three stages, and you see the map lookup before you see a price.
We look up your parcel on the city’s Wildland Urban Interface map and confirm whether you are in the WUI Area and, if so, which class. If you are outside city limits, we check the county map instead.
We roof and not as a whole-house hardening job, and we assemble the product listings for each element from our Colorado fire-resilient home materials page.
Installation follows the manufacturer’s specification, the city inspects, and you receive the closed permit together with the listing documents a buyer or insurer may later ask to see.
A code that has been on the books since 2014 rewards a contractor who has been submitting to it since 2014. We have, and three things follow from that.
Planning a roofing, siding, window, or deck project in Boulder is also an opportunity to improve your home’s fire resilience. GS Exterior Experts can help you compare durable exterior materials suited to your goals, property, and project scope.
Our team will inspect the exterior, discuss practical options, and prepare a clear estimate for the work you choose. Call (720) 683-6288 or complete our estimate form to schedule a consultation at your Boulder home.
The city’s Wildland Urban Interface map is online and searchable by address. We check it for every estimate. If you are in the mapped area, the map also shows your ignition-resistant construction class.
No. The city limits the code to the scope of the permit, so a roof permit brings only the roof assembly requirements. Siding comes up only when you pull a siding permit.
Not quite. Both are built on the 2024 International Wildland-Urban Interface Code, but Boulder adopted the base code directly with its own amendments and map, uses three classes instead of the state’s two, and took effect on August 1, 2025, ahead of the state’s July 2026 deadline.
Those neighborhoods are unincorporated Boulder County, which enforces its own ignition-resistant construction rules under the county building code, with Wildfire Zones and a Wildfire Partners certification path. The county’s updated code applies to permits from July 1, 2026. We work under both, and step one is confirming which one governs your address.
Under the city’s code, fuel modification applies only to new construction. Existing homes have general site maintenance expectations, but a siding or roofing permit does not trigger a vegetation clearing requirement.
Our free guide to the Colorado wildfire code for homeowners covers the classes, the triggers, and the product categories in ordinary language, and Boulder Fire-Rescue offers a free Detailed Home Assessment that walks your property with you.
