Insulation in Casco, Maine

Insulation and air sealing in Casco

Casco runs to about 31 square miles and roughly 3,696 people. It sits about 24 miles northwest of downtown Portland. That is roughly 2,973 housing units. The community dates back to 1841. We cover ZIP codes 04015 and 04077.

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

The housing stock in Casco

The typical home in Casco dates to around the late-1980s. Houses of this vintage usually got batts or blown fiber at whatever the standard of the day was, which is well short of what is recommended now. Most are one top-up away from being right.

We work across Casco rather than one corner of it — South Casco, Cook Mills, Crescent Lake and Pike Corner included. Construction and vintage change between them, sometimes by thirty years and a whole different framing method, which decides whether a wall can be dense-packed at all.

Casco reaches the shore of Sebago Lake and holds part of Sebago Lake State Park, one of Maine's five original state parks, with South Casco set between Sebago Lake and Thomas Pond. It was set off from Raymond in 1841, and pond outlets once ran a string of small mills.

Casco homes in the Census numbers

The Census Bureau estimates 2,973 homes in Casco. 138 of them (5%) went up before 1940 — one of the five lowest pre-1940 shares among the 64 places on this site. The 2000s were the busiest decade, adding 589 of today's homes (20%); 36% predate 1980 and 31% were built in 2000 or later. For Cumberland County as a whole the pre-1940 share is 23%, so Casco sits below it.

Of 1,663 occupied homes, 1% heat with utility gas and 7% with electricity; another 18% burn propane or other tank gas. Electric heat here is less common than across the county (15%), and ranks 38th of 64 on this site. Whoever comes out will ask what heats the house first: the rebate is the same on any fuel, but the saving is not.

90% of occupied homes are owner-occupied and 76% of all homes are single-family detached houses, with 600 mobile homes in the count. With houses like these, the conversations we expect most are about air sealing on newer houses that already have depth.

2,973 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 1,663 occupied.

Sealing comes first in Casco

994 of Casco's 2,973 homes (33%) 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 Casco

Casco enforces the Maine Uniform Building and Energy Code (2021 IECC with Maine amendments). Casco, with 3,646 residents, is not required to enforce the state code, but it posts the state's notice of the 2021 codes and uses its own Town of Casco MUBEC energy compliance certificate.

For new work, the attic number under that edition is R-60, with walls at R-30, or R-20 + R-10 continuous, or R-13 + R-15 continuous, or R-20 continuous. Set that against the Department of Energy, which recommends R60 for an uninsulated attic in this climate zone and R49 for one that already has a few inches.

The 2021 IECC insulation table (R402.1.3), climate zone 6; Maine's energy chapter changed the wood-frame wall entry and left the attic at R-60.

Do you need a permit to insulate here?

There is no published answer for Casco. Neither the permit-required list nor the exemption list mentions insulation or air sealing at all. Casco's fee schedule prices residential alterations by cost, from $20 for work up to $500, and doubles the fee for work started without a permit; it does not say whether insulation needs one. 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 Casco

The published number is 207-627-4515. The department page is here.

Permitting is on us, not on you.

Rebates a Casco homeowner can actually use

60% of the occupied homes in Casco burn fuel oil or kerosene for heat, 7% use electricity and 18% propane or other tank gas (Census ACS 2020–2024). For Casco homeowners the rebate is Efficiency Maine's: $2,000 for each attic, wall or basement zone of 500 square feet or more at any income ($3,000 moderate, $4,000 low income), with $150 to $300 for attic air sealing on top. Only a Residential Registered Vendor can do rebated work, the claim goes in within six months, and a lifetime limit of $8,600 per home applies. Income-qualified households in Cumberland County can apply to Community Concepts Inc (207-795-4065) for free weatherization through MaineHousing instead. The Cumberland County page and the rebate guide carry the full rules.

Nearby

Casco borders Naples, Raymond, Sebago, Otisfield, Poland and Sebago Lake. These are the ones we also cover, each with its own energy code and permit rule:

Elsewhere in Cumberland County we also cover:

How Casco 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 2 of the 7 publish a permit rule for insulation.

All 25 Cumberland County jurisdictions side by side →

Common questions about insulation in Casco

Code and permit facts checked October 24, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: cascomaine.org (2, 3, 4, 5) · townofnaples.org · legislature.maine.gov · www2.census.gov · maine.gov (2) · en.wikipedia.org (2, 3) · zip-codes.com · tigerweb.geo.census.gov · efficiencymaine.com (2, 3, 4) · energystar.gov · data.census.gov. These change; confirm with the building department at 207-627-4515 or Efficiency Maine at 866-376-2463 first.