Home energy audits: the $100 step that unlocks everything
A blower door, an infrared camera, a combustion safety check and a prioritized report. In New Hampshire it costs $100 and comes with free hardware. In Vermont it is the gate to the 90% rebate.
Why this is step one in both states
Neither New Hampshire nor Vermont will pay you 75–90% to insulate a house nobody has measured. The assessment is how the program knows what to fund, how the contractor knows what to scope, and how you find out whether the problem you think you have is the problem you actually have.
That last part matters more than homeowners expect. People arrive certain they need new windows — the most visible, most expensive, worst-payback upgrade in the catalogue — and leave with a report showing that the attic plane and the rim joist account for most of the loss, at a fifth of the cost and with a much larger rebate attached.
What each state charges
| New Hampshire | Vermont | |
|---|---|---|
| Program | Home Performance with ENERGY STAR | Efficiency Vermont home energy assessment |
| What you pay | $100 copay | Varies by contractor; gates the 90% rebate |
| Actual value | $400–$600 | Comparable |
| Free items installed on the day | $150–$400 of LEDs, smart power strips, low-flow showerheads, aerators | Direct-install measures vary by program |
| Income-qualified | Free, through your Community Action Agency | Free, through SEVCA or Capstone Community Action |
You pay $100. You receive a $400–$600 diagnostic workup, and the technician installs $150–$400 of hardware before leaving. Even if you never proceed to the insulation work, you are ahead on the day — and you now have a written, prioritized list of what your house actually needs.
What happens during the visit
Two to four hours, depending on the size and complexity of the house.
The blower door
A calibrated fan in an exterior doorway depressurizes the house and measures how much air it exchanges with outside, reported in air changes per hour at 50 pascals. This is your baseline number. A tight new house might be 2–3 ACH50. An unimproved Upper Valley farmhouse is frequently 12–20. With the fan running, the technician walks the house finding leaks by hand — and you should walk with them, because feeling the air pour in at the top of a partition wall is more persuasive than any report.
Thermal imaging
An infrared camera shows missing insulation, thermal bridging, wind-washed batts and wet spots inside walls and ceilings without opening anything up. Most useful on a cold day, which is one argument for booking the audit in the heating season.
Insulation and envelope inspection
Attic depth and type, wall cavity investigation (often a small borescope hole in a closet), basement and crawlspace condition, rim joist, foundation type, windows and doors, and the condition of any attached ell or addition — frequently the worst part of an old house here.
Combustion safety
The non-negotiable part. Draft testing on the boiler, furnace and water heater, carbon monoxide measurement, and a check for backdrafting risk. This matters especially because you are about to tighten the house: an atmospherically vented appliance that drafted adequately in a leaky house may not in a tight one. A competent auditor will flag this before it becomes dangerous, and it sometimes changes the recommended scope of work.
The report
A written list of recommended measures, ranked by payback, with estimated savings and the rebates each one qualifies for. This is the document the contractor scopes from and the program funds against. Keep it.
How to get the most out of it
- Book in the heating season if you can. Thermal imaging works best with a big temperature difference across the envelope.
- Walk the house with the technician. Ask them to show you where the blower door reveals air moving. It changes how you think about the building.
- Have your fuel records ready — two or three years of oil or propane delivery slips, or electric bills. It anchors the savings estimates in what your house actually burns rather than a model.
- Ask for the ducts to be included if you have a forced-air system, so the duct work can ride the same weatherization rebate. Why that matters →
- Ask about the ell. Attached ells, back kitchens and additions on Upper Valley farmhouses are routinely the worst-performing part of the building and the easiest to overlook in a standard walkthrough.
Then what
The report gives you a prioritized list. In nearly every case here, the top items are air sealing and attic insulation — which is convenient, because those carry the largest rebate in both states. Insulation and air sealing →
You are not obliged to do any of it, and you are not obliged to use the company that did the audit. But if you want the 75–90% weatherization money, the work does need to go to a contractor enrolled in the right program — NHSaves participating in New Hampshire, Efficiency Excellence Network in Vermont.
Figures checked July 2026. Rebate programs change their amounts, caps and equipment requirements during the year, and several are capped by available funding. Confirm the current offer with the program or your contractor before you sign anything.
Home energy audit: common questions
What does a home energy audit cost?
In New Hampshire, a $100 copay for the Home Performance with ENERGY STAR assessment, against a real value of $400–$600 — and the technician installs $150–$400 of LEDs, smart power strips, showerheads and aerators while there. In Vermont, cost varies by contractor, and the assessment is what unlocks the weatherization rebate. Income-qualified households in both states get it free through their Community Action Agency.
Do I have to do the work with whoever does the audit?
No. You are free to take the report and get competing quotes. What you cannot do, if you want the weatherization rebate, is hire a contractor outside the required network — NHSaves participating in New Hampshire, Efficiency Excellence Network in Vermont.
How long does it take?
Two to four hours for a typical house, longer for a large or complicated one with additions. You should plan to be home for it, and to walk around with the technician while the blower door is running.
What is a blower door test measuring?
How much air your house exchanges with the outside, expressed as air changes per hour at 50 pascals of pressure difference. A tight new house is around 2–3 ACH50; an unimproved Upper Valley farmhouse is often 12–20. It gives you a number to improve and a way to verify that the work you paid for actually did something.
Is winter or summer better for an audit?
Winter, if you can wait for it. Thermal imaging depends on a temperature difference across the building envelope, and a January audit shows far more than a July one. That said, contractor availability is far better in spring and summer, and getting the work done before the heating season is worth more than a marginally better image.
Will the audit tell me whether to get a heat pump?
It will tell you your heat loss, which is the input to sizing one — and it will usually tell you that tightening the house first will let you buy a smaller and cheaper system. A good auditor will give you the envelope work and the equipment decision in the right order rather than selling you the equipment.
Book the audit and start the clock
It is the cheapest thing you will do and it determines everything after it. We’ll connect you with an assessor on your side of the river.