Simon Testa created the interactive for Boulder Reporting Lab using data from the City of Boulder.
Boulder is redrawing the map of its wildfire danger zone, and it’s growing dramatically.
The Boulder City Council has approved a major expansion of its wildland-urban interface (WUI), the area where homes and flammable landscapes meet. The new boundaries increase the number of affected properties from about 4,600 to more than 16,000. That means thousands more homes are now considered at higher risk of wildfire. And new construction in those areas will soon be subject to stricter building and landscaping rules.
This interactive map shows whether your home falls within the expanded WUI. And if so, what level of ignition-resistant construction may be required for new buildings or remodels in your area.
What the map labels and descriptions mean
City of Boulder city limits:
This shows the legal boundary of the city. Rules only apply to properties within city limits.
WUI :
Areas in the wildland-urban interface. If your property is here, it’s designated as higher risk and will soon be subject to wildfire-related construction regulations.
Ignition Resistant Type – Class 1, 2, 3:
These categories reflect the wildfire risk level in different parts of the WUI, based on fire modeling. They determine what kinds of materials and landscaping are required for new homes:
- Class 1: Highest risk. New homes must meet the most stringent fire-resistant construction and landscaping standards. Flammable materials — including turf grass and plants in pots — are banned within five feet of a structure.
- Class 2: Medium-high risk. Still requires fire-resistant materials but with slightly more flexibility in plantings and deck materials.
- Class 3: Lower risk within the WUI, but still subject to new rules aimed at reducing ignition risk, like using noncombustible fencing near homes.
Current Fire Hazard Severity (click on a property to view):
The old WUI boundary — before the expansion.
Expansion Fire Hazard Severity (click on a property to view):
Areas that are now being added to the WUI.
Why this matters now
Starting Aug. 1, 2025, all new construction in the WUI must follow Boulder’s new wildfire safety ordinance. These rules are aimed at preventing fires from spreading house to house — one of the key lessons from the 2021 Marshall Fire, which destroyed over 1,000 homes in neighboring Louisville and Superior.
For now, the rules apply only to new construction and certain remodels. But some city councilmembers are already pushing for broader regulations that would apply to existing homes, especially as more homeowners face rising insurance premiums or cancellations due to wildfire risk.
Want to know if your property is in the WUI? Check the map above or click here.
Want to reduce your wildfire risk? The city offers free home assessments, though demand is high.
Does anyone know of a fencing company that does fire resistant privacy fences – meaning solid surface.
So far I’ve only found these in California. This would be a booming business to start around here!
Everyone in these zones should start checking on their home owners insurance. People in the foothills just outside of Boulder had the cost of their homeowners insurance significantly raised or the policy cancelled because of having property in a zone of increased fire risk. It can take months to find another insurance company if you can find one al all, and the policy may well insure at a MUCH higher cost and deductible with lower coverage.