Insulation and air sealing for Yarmouth homes: attics, crawl spaces, rim joists and walls, starting with a free assessment of the R-value you actually have. The typical home here dates to the early-1970s, and 17% of its 3,639 homes went up before 1940.
Yarmouth runs to about 13 square miles and roughly 9,053 people. It sits about 10 miles northeast of downtown Portland. Around 3,639 housing units sit inside those boundaries. The community dates back to 1849. We cover ZIP code 04096.
No completed job in Yarmouth is logged in our records yet, and this page will say so until one is.
The typical home in Yarmouth dates to around the early-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 Yarmouth rather than one corner of it — Cousins Island, Littlejohn Island, Lower Yarmouth, Yarmouthport, Yarmouth Landing and Lanes Island 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 harbor town where the Royal River meets Casco Bay, with Cousins, Littlejohn and Lanes islands inside its limits. Ships were built in the harbor from 1818 into the 1870s, and the river's four falls powered almost sixty mills between 1674 and 1931.
The Census Bureau estimates 3,639 homes in Yarmouth. 623 of them (17%) went up before 1940 — 31st of 64 places on this site for pre-1940 housing. The 1970s were the busiest decade, adding 777 of today's homes (21%); 66% predate 1980 and 11% were built in 2000 or later. For Cumberland County as a whole the pre-1940 share is 23%, so Yarmouth sits below it.
Of 3,506 occupied homes, 16% heat with utility gas and 12% with electricity; another 9% burn propane or other tank gas. Electric heat here is less common than across the county (15%), and ranks 19th 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.
80% of occupied homes are owner-occupied and 76% of all homes are single-family detached houses. On a housing mix like this, the likely starting points are an attic top-up over postwar fiberglass.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 623 | 17% | |
| 1940s | 31 | 1% | |
| 1950s | 310 | 9% | |
| 1960s | 644 | 18% | |
| 1970s | 777 | 21% | |
| 1980s | 600 | 16% | |
| 1990s | 244 | 7% | |
| 2000s | 195 | 5% | |
| 2010s | 133 | 4% | |
| 2020 or later | 82 | 2% |
3,639 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 3,506 occupied.
1,731 of Yarmouth's 3,639 homes (48%) 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.
Yarmouth enforces the Maine Uniform Building and Energy Code (2021 IECC with Maine amendments). Yarmouth's MUBEC notice says the 2021 International Energy Conservation Code has been enforced since April 7, 2025, and the town posts a fact sheet on the 2021 IECC stretch code standards.
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.
Nothing Yarmouth publishes settles this. Its permit lists name the work types it cares about, and insulation is not among them in either direction. Yarmouth charges residential renovations $10 per $1,000 of general-trades cost, $50 minimum, and its checklist leaves out items the state code exempts from permits Applications wait about 30 days on average before review. So we ask the department directly before the first day on site, and whatever comes back, pulling it is our job rather than yours.
The published number is 207-846-2401. The department page is here.
Permitting is on us, not on you.
Heating fuel in Yarmouth, by the Census Bureau's count: fuel oil or kerosene in 58% of occupied homes, electricity in 12%, propane or tank gas in 9%, and 16% utility gas (Census ACS 2020–2024). For Yarmouth 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. 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. 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
Yarmouth borders Cumberland, Freeport, North Yarmouth, Chebeague Island, Royal River and Casco Bay. 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 2 of the 7 publish a permit rule for insulation.
| City | Energy code | Attic R required | Permit to insulate | Building dept. |
|---|---|---|---|---|
| Yarmouth | Maine code, 2021 IECC | R-60 | Not published | 207-846-2401 |
| Cumberland | Maine code, 2021 IECC | R-60 | Not published | 207-829-2207 |
| Freeport | Maine code, 2021 IECC | R-60 | Not published | 207-865-4743 |
| North Yarmouth | Maine code, 2021 IECC | R-60 | Not published | 207-829-3705 |
| Baldwin | Not published | — | Not for an attic top-up | 207-625-3581 |
| Bridgton | Maine code, 2021 IECC | R-60 | Not for an attic top-up | 207-803-9963 |
| Brunswick | Maine code, 2021 IECC | R-60 | Not published | 207-725-6660 |
All 25 Cumberland County jurisdictions side by side →
Yarmouth 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.
Not on paper: Yarmouth names neither a permit nor an exemption for insulation, so one call to the department at 207-846-2401 settles it first.
The statewide Efficiency Maine rebates: $2,000 to $4,000 per insulated zone of 500 square feet or more, by income tier, and $150 to $300 for attic air sealing; the work has to be done by a Residential Registered Vendor and the attic has to start at R-21 or less. The federal 25C credit ended for work placed in service after December 31, 2025.
The typical home in Yarmouth dates to around the early-1970s; the Census Bureau's 2020-2024 median year built is 1973. Of its 3,639 homes, 17% went up before 1940 and 11% in 2000 or later. That is a median across the whole place, so your own house may be older or newer.
Code and permit facts checked October 24, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: yarmouth.me.us (2, 3, 4, 5, 6, 7, 8) · 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 207-846-2401 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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