Attic insulation, air sealing, crawl spaces and walls for homes in Westbrook — starting with a free assessment that measures the R-value you actually have. The typical home here dates to the mid-1970s, and 25% of its 9,575 homes went up before 1940.
Westbrook runs to about 17 square miles and roughly 20,775 people. It sits about 6 miles northwest of downtown Portland. That is roughly 9,575 housing units. The community dates back to 1814. We cover ZIP codes 04092 and 04098.
Our job history shows nothing in Westbrook so far. Plenty of sites will show you a number here anyway.
The typical home in Westbrook 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.
We work across Westbrook rather than one corner of it — Cumberland Mills, Frenchtown, Prides Corner, Deer Hill, Birdland, Highland Lake, The Hamlet, Woodland, Colonial Village and Westbrook Pointe 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.
A mill city on the Presumpscot River, first called Saccarappa after the falls that powered its sawmills, with a large paper mill at Cumberland Mills. It was set off from Falmouth as a town in 1814 and became a city in 1891.
The Census Bureau estimates 9,575 homes in Westbrook. 2,373 of them (25%) went up before 1940 — 7th 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 56% predate 1980. For Cumberland County as a whole the pre-1940 share is 23%, so Westbrook sits above it.
Of 9,138 occupied homes, 19% heat with utility gas and 17% with electricity; another 11% burn propane or other tank gas. Electric heat here is more common than across the county (15%), and ranks 6th 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.
61% of occupied homes are owner-occupied and 44% of all homes are single-family detached houses, with 627 mobile homes in the count. On a housing mix like this, the likely starting points are wall insulation for walls built empty and a vermiculite check before anything is disturbed.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 2,373 | 25% | |
| 1940s | 474 | 5% | |
| 1950s | 663 | 7% | |
| 1960s | 742 | 8% | |
| 1970s | 1,084 | 11% | |
| 1980s | 1,248 | 13% | |
| 1990s | 659 | 7% | |
| 2000s | 855 | 9% | |
| 2010s | 1,160 | 12% | |
| 2020 or later | 317 | 3% |
9,575 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 9,138 occupied.
2,489 of Westbrook's 9,575 homes (26%) date from 1950 through 1979. The leaks in houses of that era repeat: nothing over the top plates, wire and pipe holes left open, an unsealed hatch, a bath fan venting into the attic, and in ranches and split-levels, heat lost at the garage ceiling and over cantilevered floors. Sealing the plates, holes and fans comes before any more fiber, and it is usually a day's work, not a renovation.
Westbrook enforces the Maine Uniform Building and Energy Code (2021 IECC with Maine amendments). Westbrook's Codes in Effect page lists the 2021 International Energy Conservation Code among the state codes the city enforces, and Chapter 123 of the City Code holds alterations and repairs, not only new building, to the state code.
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 Westbrook sits, and R49 where there are already a few inches up there.
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.
There is no published answer for Westbrook. Neither the permit-required list nor the exemption list mentions insulation or air sealing at all. Westbrook's general residential building permit covers renovations and alterations, and office staff help with projects that fit no listed category; insulation has no permit type of its own. Building permits cost $50 plus $15 per $1,000 of construction cost. That silence is not permission and it is not a prohibition. We settle it with a phone call before the crew is scheduled.
The published number is 207-854-0638. The department page is here.
Permitting is on us, not on you.
In Westbrook, 49% of occupied homes heat with fuel oil or kerosene, 11% with propane or other tank gas and 17% with electricity, and 19% utility gas (Census ACS 2020–2024). For Westbrook 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. It applies to work completed on or after October 1, 2026 by one of its Residential Registered Vendors, and an attic qualifies only if it starts at R-21 or less. Income-qualified households in Cumberland County can apply to Community Concepts Inc (207-795-4065) for free weatherization through MaineHousing instead. See the rebate guide for the tiers and the checklist, and the Cumberland County page for the county.
Every layer of an insulated attic, explained
Westbrook borders Portland, South Portland, Scarborough, Gorham, Windham and Falmouth. These are the ones we also cover, each with its own energy code and permit rule:
Elsewhere in Cumberland County we also cover:
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.
| City | Energy code | Attic R required | Permit to insulate | Building dept. |
|---|---|---|---|---|
| Westbrook | Maine code, 2021 IECC | R-60 | Not published | 207-854-0638 |
| Portland | Maine code, 2021 IECC | R-60 | Not published | 207-874-8703 |
| South Portland | Maine code, 2021 IECC | R-60 | Not published | 207-767-7603 |
| Scarborough | Maine code, 2021 IECC | R-60 | Not published | 207-730-4040 |
| Gorham | Maine code, 2021 IECC | R-60 | Not published | 207-222-1605 |
| Windham | Maine code, 2021 IECC | R-60 | Not published | 207-894-5960 |
| Falmouth | Maine code, 2021 IECC | R-60 | Not published | 207-699-5310 |
All 25 Cumberland County jurisdictions side by side →
Westbrook enforces the Maine code, 2021 IECC, which sets R-60 for an attic in new work. That code also reaches work on existing houses, not only new ones.
Westbrook has not published a rule for it; the building department at 207-854-0638 is called before the job starts.
Efficiency Maine's: $2,000 per attic, wall or basement zone of 500 square feet or more at any income, $3,000 at moderate income and $4,000 at low income, plus $150 to $300 for attic air sealing, on work completed by one of its Residential Registered Vendors on or after October 1, 2026. The federal 25C credit ended for work placed in service after December 31, 2025.
The typical home in Westbrook dates to around the mid-1970s; the Census Bureau's 2020-2024 median year built is 1975. Of its 9,575 homes, 25% went up before 1940 and 24% in 2000 or later. It is a median for the place, not a survey of individual houses.
Code and permit facts checked October 24, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: westbrookmaine.gov (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 207-854-0638 or Efficiency Maine at 866-376-2463 first.
Free assessment, measured at the hatch, with the photographs and the number in writing.
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