Why it's required
Mass Save won't approve a heat pump or insulation rebate without a completed assessment on file. It's not a sales visit — it's the mechanism that determines exactly what your home qualifies for and confirms your baseline condition before any work starts.
Booking it
Schedule through Mass Save's website or by phone. You'll need to be a residential customer of a participating utility — Eversource, National Grid, Unitil, Cape Light Compact, Berkshire Gas, or Liberty Utilities. National Grid customers can also book directly at 1-866-527-7283. If your electricity comes from a municipal light plant instead, this specific assessment isn't available to you (though you may have other options — that's a separate topic, covered in our MLP towns guide).
National Grid reports the average value of weatherization work identified through the assessment is over $4,000, and 95% of participants say they'd recommend it — for a free visit with no obligation, that's a reasonable bet.
What happens during the visit
Plan for 1.5 to 2.5 hours, depending on your home's size. The assessor walks through:
- Attic: current insulation depth and type, air leaks around the hatch and fixtures
- Basement and crawlspace: insulation, moisture signs, rim joist condition
- Exterior walls: insulation level (checked via small test holes in some cases)
- Heating and cooling system: age, fuel type, efficiency rating, condition
- Water heater: age and type
- Windows and doors: general condition and count
- Blower door test (sometimes): measures overall air leakage in the home
What you get on the spot
Many assessors install free items during the visit itself:
- LED light bulbs
- Water-saving showerheads and faucet aerators
- A programmable or smart thermostat (in some cases)
- Basic weatherstripping or door sweeps
What you get afterward
A written report showing:
- Which upgrades your home qualifies for
- Estimated rebate amount for each
- Recommended priority order (usually insulation and air sealing before heat pump, since a tighter building envelope changes what size heat pump you need)
- A list of Mass Save-participating contractors in your area
What it doesn't do
The assessment doesn't submit your rebate application — that happens after you complete the actual work with an approved contractor. It also doesn't guarantee your final rebate amount; the number in your report is an estimate based on what the assessor observed, and can shift slightly depending on the exact equipment and materials your contractor uses.
How to prepare
- Clear access to your attic hatch, basement, and crawlspace if you have one
- Have your last 12 months of utility bills handy — some assessors ask for these
- Make a list of any comfort issues (cold rooms, drafts, humidity) to mention
- Ask directly what your home qualifies for at each income tier — some assessors won't volunteer the income-qualified numbers unless you ask
Next steps
Once you have your assessment report, compare it against real numbers for your city: see the full Massachusetts rebate breakdown, or if your rebate check is taking longer than expected after the work is done, here's what to do about it.