California Homeowners

How much can weatherizing save you in California?

Enter your home details to see estimated energy savings, available utility rebates, and payback period for insulation, air sealing, and window upgrades.

$200+
avg. annual energy savings
up to $3,000
SMUD rebate available
15%+
typical heating/cooling reduction
1 Your home

Older homes typically have more room for improvement and higher savings potential.

Hotter and colder climates see larger savings from weatherization.

$200 / month
$50$600

Use your average across all seasons.

2 Current insulation and upgrades planned

Check your attic: if you can see the joists, you definitely need more insulation.

Insulation and air sealing together deliver the best return. Windows add comfort but have longer payback.

3 Your utility and eligibility

Rebate availability varies significantly by utility. SMUD has the most generous weatherization rebates in California.

Income-qualified households may receive free weatherization through the utility Energy Savings Assistance Program or LIHEAP.

SMUD Seal and Insulate rebate up to $3,000

Rebate availability varies by utility and is funded annually. Verify current amounts before signing a contract.

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Fill in your details and click Calculate my savings to see your personalized estimate.

Why attic insulation is the highest-ROI upgrade

Heating and cooling account for 40 to 50% of the average California energy bill. Attic insulation is typically the single highest-return weatherization upgrade because heat rises and an uninsulated attic is essentially an open window to the sky. Most California homes built before 1990 have R-11 to R-19 attic insulation; DOE recommends R-38 to R-60 for California's climate zones.

Air sealing: the invisible upgrade

Air leaks in the average California home account for 25 to 40% of heating and cooling energy loss. Gaps around recessed lights, attic hatches, plumbing penetrations, and electrical outlets add up to the equivalent of leaving a window open year-round. Air sealing combined with insulation consistently delivers better results than insulation alone.

California utility rebates for weatherization

SMUD offers up to $3,000 for attic insulation and air sealing combined through its Home Performance Program, requiring a participating contractor. PG&E, SCE, and SDG&E offer smaller rebates through their energy efficiency programs, and all four utilities provide free weatherization to income-qualified customers through the Energy Savings Assistance Program.

When windows make sense

Window replacements have longer payback periods (10 to 20 years) than insulation and air sealing (3 to 8 years), but deliver meaningful comfort improvements. Single-pane windows lose 10 times more heat than an insulated wall. If your home has single-pane windows and you are already doing insulation work, bundling window upgrades with the same contractor can reduce labor costs significantly.

2026 California Guide

Is weatherizing your home worth it in California in 2026?

Home weatherization is one of the most consistently overlooked home improvement investments in California. While solar and battery storage get most of the attention, insulation and air sealing typically deliver payback periods of 3 to 8 years with no moving parts, no maintenance, and savings that compound every year. Utility rebates from SMUD, PG&E, SCE, and SDG&E are the primary financial incentive available in 2026.

What weatherization actually covers

Weatherization is a whole-home approach to reducing energy loss. The core upgrades are attic insulation, air sealing, and duct sealing. Secondary upgrades include floor and wall insulation, window replacements, and door replacements. A good contractor starts with a home energy audit using a blower door test to measure air leakage before recommending a scope of work. The audit itself typically costs $150 to $400 and is often rebated or credited toward the project cost.

Attic insulation is usually the first recommendation because it addresses the largest single source of heat loss in most California homes. The DOE recommends R-38 to R-60 for California's warmer climate zones and R-49 to R-60 for mountain and cold valley climates. Most pre-1990 homes have R-11 to R-19 and gain significant savings from an upgrade.

The SMUD Home Performance Program: California's best weatherization rebate

SMUD customers in the Sacramento area have access to the most generous weatherization rebates in California. The SMUD Seal and Insulate rebate pays up to $3,000 for attic insulation combined with air sealing, submitted by a participating contractor in the SMUD Contractor Network. Projects must meet program specifications for minimum R-value improvements and air sealing scope. The rebate is funded annually and processed on a first-come, first-served basis.

SMUD's Home Performance Program also allows stacking: if you complete insulation, a heat pump HVAC system, and a heat pump water heater in the same project, total rebates can exceed $10,000. The rebate is submitted by the contractor on your behalf, and payment typically arrives within two weeks of approval.

PG&E, SCE, and SDG&E weatherization rebates

PG&E, SCE, and SDG&E offer smaller weatherization rebates through their Home Energy Efficiency programs, typically $150 to $500 for attic insulation depending on current conditions and R-value improvement. These programs are also administered through participating contractors and require a pre-project assessment. Amounts and availability change annually, so confirm at your utility's website before signing a contract.

All four utilities also offer free weatherization through their Energy Savings Assistance (ESA) programs for customers who qualify for the CARE or FERA income assistance programs. If you currently receive a discount on your utility bill through CARE or FERA, you likely qualify for free insulation, air sealing, and other upgrades at no cost through the ESA program. This is the highest-value pathway for income-qualified households and should be the first call before paying out of pocket.

Go deeper

The California Home Weatherization Buyer's Guide

Ready to get quotes? This guide covers everything: understanding your home's energy audit, stacking SMUD and utility rebates, vetting contractors, and what to check before and after installation.

SMUD rebate walkthrough
15 questions to ask every contractor
Insulation R-value guide by climate zone
Air sealing scope checklist
Bid comparison worksheet
Install day sign-off checklist
Income-qualified program guide
Downloadable PDF, instant delivery
Get the guide $7 → One-time · Instant PDF download
14
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Frequently asked questions

This calculator uses DOE weatherization energy savings data, California utility rate averages, and home age and size multipliers to estimate annual savings. Actual savings depend heavily on your home's specific construction, the quality of existing insulation, and how well the new work is installed. Treat this as a solid directional estimate. A contractor's blower door test before and after installation will give you the most accurate picture of your specific home.
A professional home energy audit using a blower door test typically costs $150 to $400 for a California home. Many SMUD and PG&E participating contractors include or credit the audit cost toward the weatherization project. An audit is strongly recommended before insulation and air sealing work: it identifies where air is actually leaking (which is often not where you'd expect), sets a baseline for measuring improvement, and helps justify rebate applications. Some income-qualified programs include a free audit.
SMUD's Seal and Insulate rebate pays up to $3,000 for attic insulation combined with air sealing, submitted by a contractor in the SMUD Contractor Network. The work must meet program specifications for minimum R-value improvements. The rebate is submitted by your contractor and paid within approximately two weeks of approval. Rebates are subject to funding availability and processed first-come, first-served. Verify current availability at smud.org before signing a contract.
No. The Section 25C Energy Efficient Home Improvement Credit, which previously provided a 30% credit up to $1,200 for insulation, air sealing, and windows, was terminated for projects completed after December 31, 2025, by the One Big Beautiful Bill Act. If you completed qualifying work before that date, you may still be able to claim it on your 2025 tax return. For 2026 projects, utility rebates like SMUD's are the primary financial incentive available.
The Energy Savings Assistance (ESA) Program is a utility-administered program that provides free weatherization upgrades to income-qualified customers of PG&E, SCE, SDG&E, and SoCalGas. If you currently receive a discount on your utility bill through the CARE or FERA programs, you likely qualify. Services include attic insulation, air sealing, duct sealing, weatherstripping, and in some cases appliance replacements. There is no cost to the customer. Contact your utility to apply.
For SMUD customers, use the SMUD Contractor Network at smudcontractornetwork.org. For PG&E, SCE, and SDG&E customers, look for contractors enrolled in your utility's Home Energy Efficiency program. In all cases, look for contractors certified by the Building Performance Institute (BPI) or HERS-rated. Always verify the contractor's CSLB license number at cslb.ca.gov before signing anything, and get at least three quotes. A contractor who won't provide references or pull permits is a red flag.
Attic insulation and air sealing for a typical California home typically takes one full day. Larger homes or homes with complex attics may take two days. Window replacement adds time depending on the number of windows. Most contractors complete the work in a single visit after a pre-project assessment. You do not need to leave your home during the work, though you should expect some noise and limited attic access during installation.