Simon Testa created the Interactive For Boulder Reporting Lab using data from the city of Boulder.
Boulder redesigns the map of his forest fire zone and grows dramatically.
The city council of Boulder has approved a significant expansion of its Wildland Urban border area (WUI), the area in which houses and flammable landscapes meet. The new borders increase the number of properties affected from around 4,600 to more than 16,000. This means that thousands of other houses are now considered a higher risk of forest fire. And new buildings in these areas will soon be subject to stricter buildings and landscape buildings.
This interactive card shows whether your home falls into the extended WUI. And if so, what is necessary for new buildings or conversions in your region.
What the card names and descriptions mean
City of Boulder City Limits:
This shows the legal limit of the city. Rules only apply to real estate within the city limits.
Wui :
Areas in the interface between the Wildland and the city. If your property is here, it will be classified as a higher risk and will soon be subject to hard -working building regulations.
Fill -resistant type 1, 2, 3:
These categories reflect the forest fire risk in different parts of the WUI, based on fire modeling. You determine which types of materials and landscape design are required for new houses:
- Class 1: High risk. New houses have to meet the strictest fire-proof building and landscape standards. Boilable materials – including lawn grass and plants in pots – are prohibited by a structure within five feet.
- Class 2: Medium high risk. Still require fire -resistant materials, but with a little more flexibility in plantings and cover materials.
- Class 3: However, a lower risk within the WUI is still subject to new rules that aim to reduce the tongue risk, e.g.
Current severity of the fire risk (click on a property to display it):
The old Wui border – before the expansion.
Severity of the risk of expansion (Click on a property to display):
Areas that are now added to the WUI.
Why is that important now
From August 1, 2025, the entire new building in the WUI must follow the new forest fire regulation of Boulder. These rules aim to prevent fires from spreading the house into the house – one of the most important lessons from the Marshall fire from 2021, which destroyed over 1,000 houses in neighboring Louisville and superior.
At the moment, the rules only apply to new buildings and certain conversions. However, some city council members are already urging more extensive regulations that would apply to existing houses, especially since more homeowners are exposed to increasing insurance premiums or cancellations due to the forest fire risk.
Would you like to know if your property is in the WUI? Check the card above or click here.
Would you like to reduce your risk of running? The city offers free house reviews even though demand is high.