Weatherization first
Short answer: start with Mass Save’s no-cost Home Energy Assessment. It lists 75 to 100 percent off approved insulation and no-cost targeted air sealing, and for most homes built before 2000 it is what makes you eligible for the whole-home heat pump rebate.
Source: Mass Save: home energy assessments (Internet Archive copy, July 3, 2026) and Mass Save: air source heat pumps (July 16, 2026).
Why it comes first
- A smaller, cheaper system. A tighter home needs less heat, so the heat pump your installer sizes can be smaller. Mass Save says insulation and air sealing can lower heating and cooling costs by up to 15 percent.
- It is the rule for the big rebate. The whole-home heat pump rebate requires the home to be sufficiently weatherized. You meet it if any one of these is true: the home was built in 2000 or later; a Home Energy Assessment recommends less than $1,000 of weatherization; or weatherization recommended in 2013 or later has been completed. If you do not meet it, you may still get the partial-home amount.
- It costs the least. The assessment is no cost, and the insulation incentive is 75 to 100 percent.
What the assessment includes
- An Energy Specialist looks for energy-saving opportunities in person or virtually, and you receive a Decarbonization Report listing the rebates and incentives you qualify for.
- 75 to 100 percent off approved insulation improvements, and no-cost targeted air sealing.
- Rebates on qualifying heating, cooling and water-heating equipment, and information on the 0% HEAT Loan.
- It is for 1 to 4 unit homes. Call 866-527-SAVE (7283) or book on masssave.com. You can use the lead vendor for your area, or choose a participating Home Performance Contractor; if you already know what you want, you can go to a Direct Weatherization installer.
Who gets 100 percent off
Income-qualified households get enhanced incentives. Separately, homes in a Designated Equity Community get 100 percent off weatherization (insulation and air sealing) recommended in an assessment, with no income check. Which communities qualify loads from your ZIP code on masssave.com, so check there. Source: Mass Save: equity communities.
Things that can block the work
Mass Save’s HEAT Loan also covers “pre-weatherization barriers”, the problems that must be fixed before insulation can go in, so tell your assessor about them. We do not have a sourced list of typical barrier costs, so ask for them in writing.
Town light department? Municipal electric customers are outside Mass Save’s electric programs. Mass Save says: “Your municipal utility is not part of the Mass Save program. Please contact them directly for energy efficiency program information.” See the town pages for RMLD and Middleton.
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