Boulder council adopts updated Wildland-Urban Interface code, approves revised WUI boundary

Boulder City Council on May 15 adopted Ordinance 86 95, updating the city's Wildland-Urban Interface (WUI) regulations to the 2024 edition of the International Wildland-Urban Interface Code with local amendments and unanimously approved a revised map showing the expanded WUI area.

The vote was 8-0 to amend and pass the ordinance; council also voted unanimously to declare the revised WUI area described in staff materials. City staff told council the adopted code focuses on hardening new construction and certain additions to reduce risk from ember-driven spot fires, while a second phase later this year will address landscaping and zoning matters.

The ordinance matters because it changes the building-permit requirements that apply to properties inside the newly drawn WUI boundary and establishes minimum construction and site standards intended to reduce the chance that embers will ignite homes and cause structure-to-structure fire spread. Brad Mueller, director of Planning and Development Services, told council staff used ember‑spread modeling and other fire science to set the boundary and said the code update is the first of several steps planned this year: "This is a fairly narrow topic about the wildfire hardening and specifically breaking it into the two parts of bringing the WUI code' which, as you know, is part of the building code forward tonight," Mueller said.

Key provisions and expected near-term impacts

- New-code scope and map: Staff presented a proposed WUI area that includes roughly 16,000 parcels inside the city limits. The map, staff said, reflects ember-spotting modeling and local conditions on Boulder's western edge. Council approved the revised map by unanimous vote.

- Permits expected: Staff estimated roughly 203 building permits per year will fall inside the revised WUI area under normal activity; about 31 of those would be new-construction permits annually and roughly 72 would be additions or alterations that could trigger specific WUI provisions depending on the work.

- Construction and site rules (high…