Quick quiz: California rebates
A few questions from the programs we track. Tap an answer to see why.
The Three Types, Straight Up
Blown-In Fiberglass
Cost installed: $1.50-$2.50 per square foot, or roughly $1,800-$3,200 for a typical 1,500-square-foot attic. R-value: about R-2.5 per inch. Best for: open attics in California's Central Valley and inland areas needing a straightforward top-up.
The cheapest way to close the gap between an old, thin attic and modern R-38 to R-49 targets used across most of California's climate zones. Fast install, doesn't settle much, and it's what most contractors default to unless you ask for an alternative.
Blown-In Cellulose
Cost installed: $1.75-$3.00 per square foot, or roughly $2,100-$3,800 for the same attic. R-value: about R-3.5 per inch. Best for: homes wanting denser fill and better sound dampening, at a modest premium over fiberglass.
Treated recycled paper that packs tighter than fiberglass, cutting air movement through the layer itself. It settles 15-20% over the first few years, so ask your installer to blow in extra depth to account for that.
Spray Foam (Closed-Cell)
Cost installed: $4.50-$8.00 per square foot for closed-cell. R-value: about R-6.5 per inch. Best for: rim joists, crawlspaces, and cathedral ceilings — the spots where air sealing matters as much as insulating value.
Foam seals gaps that blown-in material can't reach. For a standard open attic in a typical single-family home, it costs three to four times more than fiberglass for the same effective R-value, so save it for the specific problem spots rather than the whole attic.
| Type | Cost (1,500 sq ft attic) | R-value per inch | Best use |
|---|---|---|---|
| Blown-in fiberglass | $1,800-$3,200 | ~R-2.5 | Open attic top-up |
| Blown-in cellulose | $2,100-$3,800 | ~R-3.5 | Denser fill, sound dampening |
| Spray foam | Spot-priced, $4.50-$8/sq ft | ~R-6.5 | Rim joists, crawlspaces, air sealing |
What's Actually Funded Right Now
Insulation incentives shifted hard going into 2026, and most homeowners are still budgeting off outdated numbers. Here's what's true today across California, whether you're in the Bay Area, Los Angeles, Sacramento, San Diego, or the Inland Empire:
- Federal 25C tax credit: ended. The Energy Efficient Home Improvement Credit — 30% of insulation and air-sealing costs, up to $1,200/year — was terminated early by the OBBBA law for anything installed after December 31, 2025.
- HEAR / HEEHRA (income-qualified, up to $1,600 for insulation): fully reserved. California's implementation of the federal HEAR program hit its statewide funding cap on February 24, 2026 and is closed to new applicants.
- Utility income-qualified assistance programs: still running. This is separate from the exhausted HEAR funding — if your household qualifies (generally at or below 200% of the federal poverty guideline), your utility's assistance program provides free attic insulation and air sealing directly, no HEAR application needed. The program goes by different names depending on your territory: SDG&E's Energy Savings Assistance Program, PG&E's REACH, SCE's ESA Program, and equivalents through LADWP and SMUD.
- CA HOMES program: not live yet. A separate whole-home retrofit incentive (up to $8,000 for a 35%+ modeled energy reduction) is still rolling out through the California Energy Commission and wasn't open for applications as of mid-2026.
Source: SDG&E ESA Program, CPUC/CEC HEAR & HOMES program status.
What to Check Before You Buy
- Confirm your income-qualified status first: if you're near the threshold, it's worth checking before hiring a contractor — the utility assistance programs cover the full cost, not just a partial rebate.
- Air sealing first: Insulation without sealing pot lights, the attic hatch, and top plates leaks conditioned air regardless of R-value.
- Ventilation: In California's hot inland climate zones, blocked soffit vents trap heat in the attic. Confirm baffles keep airflow open.
- Get the current R-value measured: most contractors can quote more accurately — and you can judge whether the price is fair — once you know your starting point.
What to Ask Before You Sign
- "Do I qualify for my utility's income-qualified insulation program instead of paying out of pocket?"
- "What R-value am I at now, and what will I be at after?"
- "Does this quote include air sealing, or just the insulation material?"
- "Are soffit vents baffled so attic airflow stays open?"
- "What's your timeline — is CA HOMES worth waiting for, or should I move now?"
The One Number That Matters
In California's hotter inland climate zones, a well-insulated attic cuts summer air conditioning costs by roughly 10-15%. On a typical Central Valley or Inland Empire cooling bill, that's $200-$400 a year in savings. Without a rebate, a $2,000-$3,000 fiberglass or cellulose job pays back in 5-8 years on energy savings alone — slower than it would have with the now-closed HEAR rebate, but still a real return.
