Planning Board recommends 2024 Wildland-Urban Interface code update and approves expanded WUI map

The City of Boulder Planning Board voted April 15 to recommend that City Council adopt Ordinance 86-95, which would adopt the 2024 edition of the International Wildland‑Urban Interface Code with local amendments, and to update the city’s Wildland‑Urban Interface (WUI) map.

The changes are part of the city’s Wildfire Hardening Project, a council priority for 2024–25. Planning and Development Services staff told the board the draft ordinance focuses on building‑code requirements for new construction in the WUI, and that most proposed local amendments center on vegetation management and defensible‑space rules.

Lisa Hood, principal planner for Planning and Development Services, said the Planning Board’s action tonight is a recommendation to City Council and described the code update as “the building code specific change” for the larger wildfire hardening project. Chief David Lowery of Boulder Fire Rescue, who led the technical portion of the presentation, summarized the proposal as an evolution of existing city practice rather than a wholly new approach: “It’s an important subject,” he said during the presentation.

Staff described several local amendments they are seeking to add to the adopted 2024 code. Key points presented to the board include: - A new, local definition of a 0–5 foot “noncombustible zone” around buildings for new construction in the designated WUI; staff said the zone must contain “no combustible material and or vegetation.” - Requirements affecting decks, gutters and vents, and fencing: new construction fences or gate sections within about 8 feet of a building would need to be noncombustible; decking surfaces in the lower‑severity WUI category (IR‑3) would require noncombustible top surfaces (the frame could be combustible in IR‑3); vents and screening updates are carried forward from the model code. - Planting restrictions for new landscaping in certain defensible zones, including a proposal to prohibit planting of juniper species within the WUI and to prefer “low‑flammability” plants in the 5–30 foot band around structures. Staff said they will publish a longer, city‑specific plant list later in the year to coordinate wildfire, water‑wise and climate goals.

Chief Lowery and the building official, Rob Adrians, said most of the board’s changes are focused on the chapter of the WUI code that addresses vegetation management (defensible space) rather than the ignition‑resistant construction chapter, although the latter contains some updates. Hood noted the state is developing a minimum statewide WUI map and that local mapping must meet or exceed any state minimums.

Staff described the proposed WUI map change as an expansion of the area subject to the WUI code. In the presentation staff said the previous WUI map identified roughly 4,600 parcels and that the proposed map adds parcels (staff used the figure "about 1,600" during the presentation) based on ember‑cast modeling and other spatial data, especially in parts of the city where embers could travel from adjacent wildland fuels. Hood and Lowery emphasized the change would mostly add areas that fall in the less‑stringent IR‑3 category, where rules focus on vegetation and maintenance rather than extensive home hardening.

Board members asked a range of implementation questions: how the code applies to historic or landmark buildings; how retroactivity and enforcement would work; impacts on mobile home parks; how the city expects insurance markets to react; and whether the 0–5 foot noncombustible zone would worsen urban heat‑island effects. Planning and utilities staff and the director of Planning and Development Services, Brad Beeler, responded that the ordinance applies to new construction and to components replaced in the course of permitted work; retroactive requirements were not proposed, though staff will study options such as requirements at time of sale. On insurance, staff said private underwriters set rates and the city cannot compel insurers to offer coverage, but staff hopes stronger mitigation can improve the community’s risk profile.

During the public hearing the board heard one on‑line commenter, Lynn Siegel, who described an unrelated personal concern about installation and siting of equipment at her home; staff acknowledged the comment and explained the program under which the equipment had been installed.

Votes at a glance - Motion to recommend continuing a separate agenda item (4a) to a date certain (May 27) — passed (recorded affirmative roll call vote by board members present). - Motion to recommend City Council adopt Ordinance 86-95 (adopt 2024 IWUIC with local amendments) and to update the WUI map as proposed — passed; recorded roll call: Mason Yes; Laura Yes; Claudia No; Kurt Yes; Emil/ML Yes; George Yes; Chair Yes (one dissent). - Motion that Planning Board recommend City Council direct staff to research methods to protect vegetation and green space in multi‑unit housing, higher‑density zones and lots with small setbacks — passed (recorded roll call with one dissent).

What it means If City Council follows the board’s recommendation, Boulder would adopt the 2024 model WUI code with the local amendments described by staff. The code changes would apply primarily to new construction and to permitted repairs or replacements of building elements; staff emphasized the broader wildfire‑resilience program pairs code updates with outreach, detailed home assessments, incentive grants and other mitigation programs.

Next steps Staff told the board the ordinance will go to City Council for first reading on Thursday; second reading and a council public hearing are scheduled for the following month. Staff said they will mail notice and information to properties in the proposed WUI area, publish an updated plant list later in the year, and continue work on related land‑use code changes and water‑wise landscaping standards that are expected in the fall.

Sources: Presentation and Q&A with Lisa Hood (Principal Planner), Chief David Lowery (Boulder Fire Rescue), Rob Adrians (Chief Building Official), Brad Beeler (Director, Planning & Development Services); public hearing testimony.