Attic insulation, air sealing, crawl spaces and walls for homes in Topsham — starting with a free assessment that measures the R-value you actually have. The typical home here dates to the early-1980s, and 12% of its 4,313 homes went up before 1940.
Topsham runs to about 32 square miles and roughly 9,706 people. It sits about 26 miles northeast of downtown Portland. That is roughly 4,313 housing units. The community dates back to 1764. We cover ZIP code 04086.
Our job history shows nothing in Topsham so far. Plenty of sites will show you a number here anyway.
The typical home in Topsham dates to around the early-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.
The village holds Federal-style houses from the early 1800s along Main, Green, Pleasant, Winter and Elm streets, with later Greek Revival houses, Queen Anne houses on Summer Street, and Italianate porches and bay windows added to older homes.
We work across Topsham rather than one corner of it — Topsham Village, Pejepscot Village, Topsham Heights, Topsham Foreside and Pleasant Point 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.
Topsham sits on the Androscoggin River across from Brunswick, where the river runs into Merrymeeting Bay. Its village grew around sawmills, paper mills and early shipbuilding, and mill workers settled in Pejepscot Village and Topsham Heights.
The Census Bureau estimates 4,313 homes in Topsham. 536 of them (12%) went up before 1940 — 49th of 64 places on this site for pre-1940 housing. The 2000s were the busiest decade, adding 696 of today's homes (16%); 50% predate 1980 and 24% were built in 2000 or later. For Sagadahoc County as a whole the pre-1940 share is 27%, so Topsham sits below it.
Of 4,011 occupied homes, 20% heat with utility gas and 10% with electricity; another 13% burn propane or other tank gas. Electric heat here is less common than across the county (11%), and ranks 30th of 64 on this site. Efficiency Maine's insulation rebates do not depend on the fuel or the utility, but the fuel decides what the work saves, so the assessment asks how the house is heated.
79% of occupied homes are owner-occupied and 74% of all homes are single-family detached houses, with 292 mobile homes in the count. Read together, those numbers point toward the attic, which is where most houses here start.
| Built | Homes | Share | |
|---|---|---|---|
| Before 1940 | 536 | 12% | |
| 1940s | 199 | 5% | |
| 1950s | 363 | 8% | |
| 1960s | 499 | 12% | |
| 1970s | 577 | 13% | |
| 1980s | 664 | 15% | |
| 1990s | 427 | 10% | |
| 2000s | 696 | 16% | |
| 2010s | 329 | 8% | |
| 2020 or later | 23 | 1% |
4,313 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 4,011 occupied.
1,091 of Topsham's 4,313 homes (25%) 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.
Topsham enforces the Maine Uniform Building and Energy Code (2021 IECC with Maine amendments). Topsham's residential permit packet says projects follow the state's residential code, the 2021 IRC as amended, whose chapter 11 carries the energy rules, and the code enforcement page dates the 2021 codes to 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.
The 2021 IECC, Table R402.1.3, zone 6, as amended by Maine's energy rule, 08-003 C.M.R.
There is no published answer for Topsham. Neither the permit-required list nor the exemption list mentions insulation or air sealing at all. Topsham's building permit application exempts repairs and maintenance of existing buildings, replacement of non-structural elements and decorative changes, and Zoning Ordinance section 225-61 says the same of work not requiring structural elements. 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 207-729-0908. The department page is here.
Permitting is on us, not on you.
48% of the occupied homes in Topsham burn fuel oil or kerosene for heat, 10% use electricity and 13% propane or other tank gas, and 20% utility gas (Census ACS 2020–2024). For Topsham 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 Sagadahoc County can apply to Kennebec Valley Community Action Program (207-859-1500) for free weatherization through MaineHousing instead. See the rebate guide for the tiers and the checklist, and the Sagadahoc County page for the county.
Every layer of an insulated attic, explained
Topsham borders Brunswick, Bowdoin, Bowdoinham, Durham, Lisbon and Androscoggin River. These are the ones we also cover, each with its own energy code and permit rule:
Elsewhere in Sagadahoc 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. |
|---|---|---|---|---|
| Topsham | Maine code, 2021 IECC | R-60 | Not published | 207-729-0908 |
| Brunswick | Maine code, 2021 IECC | R-60 | Not published | 207-725-6660 |
| Bowdoin | Not published | — | Not published | 207-250-2399 |
| Bowdoinham | Not published | — | Not published | 207-666-5531 |
| Arrowsic | Not published | — | Not published | 207-295-4332 |
| Bath | Maine code, 2021 IECC | R-60 | Not published | 207-443-8334 |
| Georgetown | Not published | — | Not published | 207-295-4332 |
All 10 Sagadahoc County jurisdictions side by side →
Topsham 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.
Topsham has not published a rule for it; the building department at 207-729-0908 is called before the job starts.
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 Topsham dates to around the early-1980s; the Census Bureau's 2020-2024 median year built is 1980. Of its 4,313 homes, 12% 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: topshammaine.com (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14) · maine.gov (2) · en.wikipedia.org (2, 3) · topshamlibrary.org · pressherald.com · zip-codes.com (2) · efficiencymaine.com (2, 3, 4) · energystar.gov · data.census.gov. These change; confirm with the building department at 207-729-0908 or Efficiency Maine at 866-376-2463 first.
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