Fire setbacks on the roof

California’s residential code and the City of Los Angeles fire department require open strips on roofs with solar. A layout that ignores them won’t pass plan review, so the editor shows them from the first face you draw.

What you see

Red hatched strips along the edges of each face — usually along the ridge, and under City of LA rules along rakes, hips and valleys too. Their width comes from the edge type and the rules in Fire setbacks — on the right when Panels is picked. Press F or untick Show on the roof (F) to hide them for a moment; they still apply.

How they’re used

• Fill roof (X) places panels only outside the setbacks and around obstacles.
• A panel you drag or place into a setback turns red — see Why panels turn red.
• Under California code the ridge setback grows from 18″ to 36″ when solar covers more than a third of the roof. Fill roof notices and lays the panels out again.
• The Obstacles value keeps panels that far from chimneys, vents and skylights.

When the strips look wrong

A setback in an odd place usually means an edge got the wrong type — for example a hip marked as a rake. Select the edge and check its type: Edge types: eave, rake, ridge, hip, valley. To change the widths or the rules, see Choose fire setback rules: California, City of LA or custom.