Austin, TX Environmental Rules: Defensible Space (2026)

Austin adopted the 2024 International Wildland-Urban Interface Code in Section 25-12-181 and amended it in Section 25-12-183, effective July 10, 2025 under Ord. No. 20250410-041. The defensible space rules sit in Section 603 of that code, and the distance that applies depends on the structure's Proximity Zone. Zone A covers structures 50 feet or closer to 40 acres of wildland. Zone B covers structures more than 50 feet and up to 150 feet from 40 acres of wildland. Zone C covers structures more than 150 feet and up to 0.5 miles from 40 acres of wildland, or up to 1.5 miles from 750 acres of wildland. Table 603.2 then sets the fuel modification distance at 100 feet for Zone A, 50 feet for Zone B and 30 feet for Zone C, each ending at the property line when that comes first. The fire code official can increase any of those distances after a site-specific analysis of local conditions and the fire protection plan. Where a lot gives a structure conflicting designations, the most restrictive zone governs the entire structure. Distance to wildland is measured from the structure to the actual wildland, regardless of where the property line runs.

Every building in the interface also needs an Ember Ignition Zone, a five-foot band measured from the edge of the roof overhang, including covered decks and patios. It must be landscaped with gravel, pavers or other non-combustible material and kept clear of weeds, grass, shrubs, leaves, lawn furniture and door mats. Protected and Heritage trees can stay, but the zone is never a basis to approve their removal. Type I and II construction needs the zone only in front of and 10 feet to each side of egress points and fire systems access doors. Artificial turf is barred, and Zone C properties are allowed green, moist, closely mowed lawn grass, seeded with perennial Rye grass while dormant.

The person who owns, leases, controls, operates or maintains the building is responsible for modifying or removing nonfire-resistive vegetation and keeping it that way. Trees are allowed inside defensible space if they are maintained to stop fire entering or spreading through canopies, and pruning should focus on limbs under the eaves and limbs less than six feet above the ground. Where the fire code official requires it, firewood and combustible material must sit at least 20 feet from structures and 15 feet horizontally from tree crowns.