Mass Save Insulation & Air Sealing Rebates

National Grid / Mass Save

Available Weatherization

About This Program

Rebates covering 75% of insulation and air sealing costs for National Grid customers, up to 100% for income-eligible households. Includes attic, wall, and basement insulation plus air sealing. Must complete Mass Save Home Energy Assessment first.

Estimate assumes 75% rebate on typical insulation project

Official program page checked live on 2026-06-17.

Data last verified 2026-06-09. How we verify our data.

Key Details

  • 75% rebate on insulation and air sealing
  • 100% rebate for income-eligible customers
  • Covers attic, walls, basement, and rim joists
  • Requires Home Energy Assessment first
  • Must use Mass Save qualified contractor

How to Apply

A grant-savvy contractor in Westborough, MA can handle the paperwork, inspections, and timelines so your funding releases on schedule. Getting matched is free.

This grant requires a licensed contractor

This grant requires the work to be done by a licensed contractor, and you will likely need a written estimate to apply. Get a free estimate from a contractor in Westborough who knows grant paperwork.

Get matched with a contractor

Each program sets its own contractor rules. Check the official program page for exact requirements.

Your application paperwork

Documents you will likely need

  • Proof you own and live in the home (deed, recent mortgage statement, or property tax bill).
  • A government-issued photo ID for every owner on title.
  • A written estimate from a licensed contractor for the work (many programs require this to apply).
  • A recent utility bill for the home (energy and weatherization programs use it to confirm service and usage).
  • Photos of the problem area or the work to be done.
  • The program's own application form, completed (use the official link or phone number on this page).

Requirements vary by program and locality. Confirm the exact rules on the official program page. We can help you prepare your paperwork, but you submit it yourself.

Deadline: Ongoing

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Need a Contractor for This Grant?

Grant-approved contractors understand the documentation, inspections, and timelines, so your funding releases on schedule.

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