Insulation in Windham, Maine

Insulation and air sealing in Windham

Windham runs to about 47 square miles and roughly 19,188 people. It sits about 12 miles northwest of downtown Portland. There are around 8,709 housing units here. The community dates back to 1762. We cover ZIP codes 04062 and 04082.

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

The housing stock in Windham

The typical home in Windham 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 Windham rather than one corner of it — North Windham, South Windham, Windham Center, Windham Hill, Newhall, Fosters Corner and Scotland 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.

Windham lies beside Sebago Lake, and North Windham grew into the town's commercial center on traffic from lake vacationers and Portland commuters. South Windham grew up as a mill village around a brick paperboard and pulp mill on the Presumpscot River.

Windham homes in the Census numbers

The Census Bureau estimates 8,709 homes in Windham. 1,015 of them (12%) went up before 1940 — 47th of 64 places on this site for pre-1940 housing. The 1980s were the busiest decade, adding 1,476 of today's homes (17%); 42% predate 1980 and 27% were built in 2000 or later. For Cumberland County as a whole the pre-1940 share is 23%, so Windham sits below it.

Of 7,900 occupied homes, 4% heat with utility gas and 10% with electricity; another 21% burn propane or other tank gas. Electric heat here is less common than across the county (15%), and ranks 28th 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.

85% of occupied homes are owner-occupied and 79% of all homes are single-family detached houses, with 272 mobile homes in the count. On a housing mix like this, the likely starting points are the attic, which is where most houses here start.

8,709 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 7,900 occupied.

Sealing comes first in Windham

2,696 of Windham's 8,709 homes (31%) 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 Windham

Windham enforces the Maine Uniform Building and Energy Code (2021 IECC with Maine amendments). Chapter 28 of Windham's Town Code adopts the state code with the code board's later revisions, which brought in the 2021 International Energy Conservation Code on April 7, 2025.

That edition sets R-60 for the attic in new work, and R-30, or R-20 + R-10 continuous, or R-13 + R-15 continuous, or R-20 continuous for walls. The Department of Energy's recommendation for this climate zone is no lower: R60 for an attic with nothing in it, R49 where a few inches are already down.

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?

Windham publishes no answer either way. Insulation and air sealing appear on neither the permit-required list nor the exempt list. Windham's building code chapter lets ordinary repairs go ahead without an application if no structural beams or bearing supports are cut, and its permit-exempt list does not name insulation; the renovation permit runs $50 for work up to $5,000. 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 Windham

The published number is 207-894-5960. The department page is here.

Permitting is on us, not on you.

Rebates a Windham homeowner can actually use

58% of the occupied homes in Windham burn fuel oil or kerosene for heat, 10% use electricity and 21% propane or other tank gas, and 4% utility gas (Census ACS 2020–2024). The insulation money for a Windham house comes from Efficiency Maine, not the electric company. For a zone of 500 square feet or more it pays $2,000 at any income, $3,000 at moderate income and $4,000 at low income, and $150 to $300 more for attic air sealing. 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. Every condition is in the rebate guide. The Cumberland County page compares the towns.

Nearby

Windham borders Gorham, Standish, Westbrook, Falmouth, Cumberland and Gray. These are the ones we also cover, each with its own energy code and permit rule:

Elsewhere in Cumberland County we also cover:

How Windham 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 none of the 7 publishes a permit rule for insulation.

All 25 Cumberland County jurisdictions side by side →

Common questions about insulation in Windham

Code and permit facts checked October 24, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: windhammaine.us (2, 3) · ecode360.com (2) · public.mygov.us · maine.gov (2) · en.wikipedia.org (2) · 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 207-894-5960 or Efficiency Maine at 866-376-2463 first.