Insulation in Cumberland, Maine

Insulation and air sealing in Cumberland

Cumberland runs to about 23 square miles and roughly 8,647 people. It sits about 9 miles north of downtown Portland. There are around 3,282 housing units here. The community dates back to 1821. We cover ZIP codes 04021 and 04110.

We have not logged a completed job in Cumberland yet. We would rather say so than put a number on this page that is not real.

The housing stock in Cumberland

The typical home in Cumberland dates to around the mid-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 Cumberland rather than one corner of it — Cumberland Center, Cumberland Foreside and West Cumberland 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.

The town runs from Cumberland Foreside on Casco Bay inland to West Cumberland at the Windham line. It split from North Yarmouth in 1821, still holds the yearly Cumberland Fair, and keeps a few working farms and orchards; Chebeague Island left to become its own town in 2007.

Cumberland homes in the Census numbers

The Census Bureau estimates 3,282 homes in Cumberland. 502 of them (15%) went up before 1940 — 37th of 64 places on this site for pre-1940 housing. The 1990s were the busiest decade, adding 529 of today's homes (16%); 46% predate 1980 and 29% were built in 2000 or later. For Cumberland County as a whole the pre-1940 share is 23%, so Cumberland sits below it.

Of 3,109 occupied homes, 23% heat with utility gas and 8% with electricity; another 12% burn propane or other tank gas. Electric heat here is less common than across the county (15%), and ranks 35th of 64 on this site. The heating fuel does not change the Efficiency Maine rebate, but it does change what each inch of insulation is worth, which is why the boiler, furnace or heat pump is the first thing an assessment looks at.

91% of occupied homes are owner-occupied and 82% of all homes are single-family detached houses, with 65 mobile homes in the count. Read together, those numbers point toward the attic, which is where most houses here start.

3,282 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 3,109 occupied.

Sealing comes first in Cumberland

845 of Cumberland's 3,282 homes (26%) 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 Cumberland

Cumberland enforces the Maine Uniform Building and Energy Code (2021 IECC with Maine amendments). Cumberland's Code Enforcement page names the 2021 International Energy Conservation Code alongside the 2021 residential and building codes the state requires.

Under that edition the required attic value for new work here is R-60, and walls R-30, or R-20 + R-10 continuous, or R-13 + R-15 continuous, or R-20 continuous. For comparison, the Department of Energy recommends R60 for an uninsulated attic in climate zone 6A, where Cumberland sits, and R49 where there are already a few inches up there.

Table R402.1.3 of the 2021 IECC for climate zone 6, with the wall row as Maine rewrote it (08-003 C.M.R.

Do you need a permit to insulate here?

Cumberland publishes no answer either way. Insulation and air sealing appear on neither the permit-required list nor the exempt list. The town's fee schedule prices renovation and alteration permits at $14 per $1,000 of cost with a $50 minimum, but its pages do not say whether an insulation job alone counts as one. We confirm it with the department before we start and pull whatever is needed. We would rather write that here than guess on your behalf.

Permits and inspections in Cumberland

The published number is 207-829-2207. The department page is here.

Permitting is on us, not on you.

Rebates a Cumberland homeowner can actually use

50% of the occupied homes in Cumberland burn fuel oil or kerosene for heat, 8% use electricity and 12% propane or other tank gas, and 23% utility gas (Census ACS 2020–2024). Efficiency Maine pays the same rebates in Cumberland 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 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

Cumberland borders Falmouth, Yarmouth, North Yarmouth, Gray, Windham and Chebeague Island. These are the ones we also cover, each with its own energy code and permit rule:

Elsewhere in Cumberland County we also cover:

How Cumberland 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 25 Cumberland County jurisdictions side by side →

Common questions about insulation in Cumberland

Code and permit facts checked October 24, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: townofcumberlandmaine.gov (2, 3, 4, 5) · maine.gov (2) · en.wikipedia.org (2, 3, 4) · 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 207-829-2207 or Efficiency Maine at 866-376-2463 first.