Question 1

Why do this before installing a heat pump?

Accepted Answer

Weatherization shrinks the heating and cooling load your heat pump has to serve. A tighter, better-insulated house often needs a 30–40% smaller heat pump — which means $4,000–$6,000 less in equipment, lower install complexity, less likely need for a panel upgrade, and a heat pump that runs in its efficient range more of the time. Weatherization first, heat pump sizing second.

Question 2

How much can weatherization realistically save me?

Accepted Answer

For an average leaky home (3+ ACH50), a thorough air seal + attic insulation project typically cuts heating and cooling bills by 15–25%. That's $300–$800/year in most climates. Combined with duct sealing in a forced-air home, savings can reach 30%.

Question 3

Is the Weatherization Assistance Program (WAP) the same as HEAR weatherization?

Accepted Answer

No. WAP is a separate, much older program for low-income households (≤200% FPL) that provides free weatherization through community action agencies. HEAR is the new IRA-funded program for ≤150% AMI households. They don't stack — you generally qualify for one or the other based on income level. If you qualify for WAP, it's usually the better deal because it's 100% subsidized.

Question 4

Does new construction qualify for weatherization rebates?

Accepted Answer

Generally no. HEAR is designed for existing-home retrofits. Code-built new construction already meets the insulation and air-sealing standards HEAR is trying to upgrade older homes to.

Question 5

Can I DIY parts of this and still get rebates?

Accepted Answer

HEAR rebates require a registered contractor. Utility rebates often do too. DIY air sealing and added attic insulation are completely worth doing on their own — it's the highest-ROI work most homeowners can do — but the rebate dollars require a pro install with a paper trail.

Weatherization rebates in Montana (2026)