Attic Insulation R-Value California Guide 2026
California requires R-30 to R-49 attic insulation depending on climate zone. Top picks plus DIY install considerations.
Most California homes built before 2008 have inadequate attic insulation (R-19 or less). Upgrading to current code (R-30 to R-49) cuts AC bills 15-25%.
Quick Comparison
| Pick | Best For | Approx Price |
|---|---|---|
| Blown-In Pick | Owens Corning AttiCat Expanding Attic Insulation | $30-$50 / bag |
Our Picks
R-Value by California Zone
- Coast (LA, SD): R-30
- Inland Valley (Sacramento, Fresno): R-38
- Mountains (Big Bear): R-49
Blown-In vs Batts
Blown-in fills around obstacles, easier DIY. Batts are cheaper per square foot but more labor.
DIY Considerations
Most home centers rent blower machines free with insulation purchase. 8-bag job: 4-5 hours. Wear N95.
Need help with installation? Book a service appointment or get a free quote. Same-day available across California.
Frequently Asked Questions
R-value for my zone?
R-30 coastal. R-38 inland valley. R-49 mountains.
Blown-in or batts?
Blown-in for retrofit. Batts for new construction with open access.
DIY cost?
$1,200-$2,000 for typical 1,500 sqft attic. Pro install: $2,500-$4,000.
Need a Pro in California?
Insured, background-checked handymen. 4.9☆ rated. Same-day available.
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