Attic Insulation Cost in Southern California (2026)

$2.25 to $4.75 per square foot installed in Southern California, so $3,375 to $7,125 for a typical 1,500 square foot attic. Removal of old material and air sealing are priced separately.

California Title 24 calls for R-38 minimum in most of climate zone 14 and 16, and R-49 is the practical target for desert homes because attic temperatures routinely exceed 140°F in July and August.

Yes. Going from a settled R-19 attic to R-49 with air sealing typically reduces summer cooling runtime 15 to 25 percent. At SCE rates near $0.28 per kWh, that is often $40 to $95 a month across the cooling season.

Remove it if it is rodent-contaminated, water-damaged, or compressed below R-13. Otherwise, blowing over clean existing material is cheaper and performs nearly the same.

In a vented attic, no — blown fiberglass or cellulose plus air sealing gives most of the benefit for far less. Closed-cell foam at the roof deck makes sense when ductwork runs through the attic and you want it inside the conditioned envelope.

Utility rebate programs change frequently and the federal 25C credit expired at the end of 2025. We check current SCE and SoCalGas program status at the time of your quote rather than promising a specific amount.