Bonner County, ID Environmental Rules: Defensible Space (2026)

Defensible space in Bonner County is a subdivision design requirement, not a standing yard maintenance rule for existing homes. Section 12-623 D, part of the subdivision standards in Title 12, says all proposed lots shall be designed by the applicant to provide a fire protection plan. At a minimum the plan must include an assessment of fire risk, plans to reduce the risk, and provisions for defensible space. The code defines defensible space as the place where material capable of allowing a fire to spread unchecked will be treated, cleared or modified to slow the rate and intensity of an advancing wildfire and to create an area for fire suppression operations to occur.

The plan must also satisfy at least one (1) of four options. Option 1 is an approved water and fire hydrant system capable of one thousand (1,000) gallons per minute for a minimum of two (2) hours prior to final plat, where a community water system exists or is proposed. Option 2 is a final plat note requiring an approved IFC residential fire suppression sprinkler system in all newly constructed residences. Option 3 is a manmade or natural water source with a dry hydrant, in place prior to final plat. Option 4 is a final plat note stating: at the time of building permit or building location permit, the lot owner shall install an approved fire suppression method to the satisfaction of Bonner County.

IFC means the international fire code as adopted by the state fire marshal, with later editions, incorporated by reference with a copy on file with the office of the clerk of the board of county commissioners. The section was adopted in Ordinance 501 and amended by Ordinances 607 and 731, the latest dated November 10, 2025. It applies to land divisions in unincorporated Bonner County, and the Board of County Commissioners sets the subdivision rules in Title 12.