Altadena is an unincorporated community in the west San Gabriel Valley. It has no city government and no city permit office, so permits come from LA County. The census puts owner-occupied single-family homes at 10,072.
A median house built in 1946
The median home was built in 1946, and in the Census Bureau's 2020 to 2024 estimates the median owner-reported value is $1,120,000. In County jurisdiction, existing wood shakes must be removed on a reroof, and clay or concrete tile has to come off completely, whatever the new material.
Climate zone 9 for a foothill community
Altadena is in climate zone 9, so the steep-slope cool roof values apply to a house replacing over half its roof: at least 0.20 reflectance after aging and 0.75 emittance, with SRI 16 as the other route. Overlays count as replacement. The County's reroofing manual allows a new covering over an existing one only when no more than one layer is present and the deck is sound.
LA County Building and Safety, and rebuilding
LA County Public Works, Building and Safety issues the building permit for a reroof here, and a separate solar permit covers taking rooftop panels off and putting them back. For rebuilding after the 2025 Los Angeles fires, the California Energy Commission reported in 2025 that, under Executive Order N-29-25, some 2025 Energy Code changes do not apply to these rebuilds. CAL FIRE's official hazard severity viewer shows the zone for an address, and LA County Building and Safety can say what that means for your permit.
Jobs we take in Altadena
Replacement and new roofs, including rebuilding. The pages on older houses and new roof installation apply here.
Altadena questions
What is the median build year in Altadena, and what gets checked on the roof?
The median build year is 1946. The assessment records the sheathing, the layers and any wood shake before a material is named.
Does the Altadena climate zone change what a reroof needs?
Zone 9. A single-family reroof of more than half the roof needs steep-slope at least 0.20 reflectance after aging and 0.75 emittance, with SRI 16 as the other route.
Which office issues reroof permits in Altadena?
LA County Public Works, Building and Safety, since Altadena is unincorporated. A reroof takes a building permit, and panels coming off and going back on take a solar permit of their own.