Insulation in Cornish, Maine

Insulation and air sealing in Cornish

Cornish runs to about 22 square miles and roughly 1,803 people. It sits about 29 miles west of downtown Portland. That is roughly 863 housing units. The community dates back to 1794. We cover ZIP code 04020.

Our job history shows nothing in Cornish so far. Plenty of sites will show you a number here anyway.

The housing stock in Cornish

The typical home in Cornish dates to around the mid-1970s. Postwar building here often meant three or four inches of fiberglass and no attempt at air sealing. If nobody has touched it since, that is what is still up there.

That includes Cornish Village and Thompson Park. Housing age and construction shift across Cornish, sometimes by decades within a few streets, which is why we look in the attic before quoting rather than after.

Cornish is a small river town where the Ossipee River meets the Saco River, with a village of antique shops and restaurants near historic Thompson Park. It holds the highest ground in York County, Clark Mountain at over 1,320 feet.

Cornish homes in the Census numbers

The Census Bureau estimates 863 homes in Cornish. 153 of them (18%) went up before 1940 — 30th of 64 places on this site for pre-1940 housing. More of today's homes date from before 1940 than from any single decade since, and 54% predate 1980. For York County as a whole the pre-1940 share is 20%, so Cornish sits below it.

Of 742 occupied homes, 0% heat with utility gas and 4% with electricity; another 9% burn propane or other tank gas. Electric heat here is less common than across the county (10%), and ranks 58th of 64 on this site. Efficiency Maine's insulation rebates do not depend on the fuel or the utility, but the fuel decides what the work saves, so the assessment asks how the house is heated.

82% of occupied homes are owner-occupied and 81% of all homes are single-family detached houses, with 82 mobile homes in the count. With houses like these, the conversations we expect most are about the attic, which is where most houses here start.

863 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 742 occupied.

Sealing comes first in Cornish

199 of Cornish's 863 homes (23%) were built in the 1980s and 1990s. The gaps in houses of that age are the parts nobody sealed: batts stuffed into the rim joist, bare spots over cathedral and tray ceilings, soffit vents buried with no baffles, can lights punched through the ceiling plane. A top-up plus a day of sealing usually covers it.

What the energy code requires in Cornish

Cornish does not publish the energy code edition it enforces, so this page does not name one. Cornish had 1,508 residents in 2020 and is not required to enforce the state code; its Land Use Ordinance carries a short building code chapter of its own for new buildings. Maine has one energy code for the whole state, the 2021 IECC with Maine's changes. A town of 4,000 or fewer people does not have to enforce it, but the state says it still applies to every building, and meeting it is the owner's responsibility.

Do you need a permit to insulate here?

There is no published answer for Cornish. Neither the permit-required list nor the exemption list mentions insulation or air sealing at all. Cornish's Land Use Ordinance requires a permit for the uses marked in its table, and its fee schedule charges renovations $10 per $2,000 of value. That silence is not permission and it is not a prohibition. We settle it with a phone call before the crew is scheduled.

Permits and inspections in Cornish

The published number is 207-653-4608. The department page is here.

Permitting is on us, not on you.

Rebates a Cornish homeowner can actually use

In Cornish, 72% of occupied homes heat with fuel oil or kerosene, 9% with propane or other tank gas and 4% with electricity (Census ACS 2020–2024). Efficiency Maine pays the same rebates in Cornish as anywhere else in the state: $2,000 per attic, wall or basement zone with 500 square feet or more insulated at any income, $3,000 for a verified moderate-income household and $4,000 for a low-income one, plus $150 to $300 for sealing the attic's air leaks. The work has to be done by an Efficiency Maine Residential Registered Vendor, and the attic has to start at R-21 or below and finish at R-49 or more. Income-qualified households in York County can apply to York County Community Action Corp (207-324-5762) for free weatherization through MaineHousing instead. Every condition is in the rebate guide. The York County page compares the towns.

Nearby

Cornish borders Hiram, Baldwin, Limington, Limerick and Parsonsfield. These are the ones we also cover, each with its own energy code and permit rule:

Elsewhere in York County we also cover:

How Cornish compares with its neighbors

Maine sets the residential energy code statewide, so the attic figure is R-60 wherever it is published here; what changes is the permit desk, and 1 of the 7 publishes a permit rule for insulation.

All 29 York County jurisdictions side by side →

Common questions about insulation in Cornish

Code and permit facts checked October 24, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: cornishme.com (2, 3, 4, 5, 6) · legislature.maine.gov (2) · maine.gov (2) · www2.census.gov (2, 3) · en.wikipedia.org · prd-tnm.s3.amazonaws.com · efficiencymaine.com (2, 3, 4) · energystar.gov · data.census.gov. These change; confirm with the building department at 207-653-4608 or Efficiency Maine at 866-376-2463 first.