Insulation in Woolwich, Maine

Insulation and air sealing in Woolwich

Woolwich runs to about 35 square miles and roughly 3,158 people. It sits about 32 miles northeast of downtown Portland. There are around 1,430 housing units here. The community dates back to 1775. We cover ZIP code 04579.

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

The housing stock in Woolwich

The typical home in Woolwich 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.

Days Ferry is a historic riverside village of well-kept older homes in Colonial, Federal and Greek Revival styles, while newer growth is steered toward the Nequasset area.

We work across Woolwich rather than one corner of it — Days Ferry, Nequasset, Montsweag, North Woolwich, Chops Point and Sagadahoc Ferry 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.

Woolwich is surrounded by water on three sides: the Kennebec River and Merrymeeting Bay to the west, Montsweag Bay to the east and the Sasanoa and Back rivers to the south. Route 1 comes over the Kennebec bridge from Bath and runs through the middle of town. Days Ferry, on the Kennebec, is a National Register village of houses from the 1700s and early 1800s.

Woolwich homes in the Census numbers

The Census Bureau estimates 1,430 homes in Woolwich. 308 of them (22%) went up before 1940 — 15th 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 49% predate 1980. For Sagadahoc County as a whole the pre-1940 share is 27%, so Woolwich sits below it.

Of 1,295 occupied homes, 1% heat with utility gas and 4% with electricity; another 11% burn propane or other tank gas. Electric heat here is less common than across the county (11%), and ranks 55th 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.

96% of occupied homes are owner-occupied and 83% of all homes are single-family detached houses, with 212 mobile homes in the count. Read together, those numbers point toward air sealing on newer houses that already have depth.

1,430 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 1,295 occupied.

Sealing comes first in Woolwich

281 of Woolwich's 1,430 homes (20%) 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 Woolwich

Woolwich does not publish the energy code edition it enforces, so this page does not name one. Woolwich had 3,068 residents in 2020 and is not required to enforce the state code. Maine has one energy code for the whole state, the 2021 IECC with Maine's changes. A town of 4,000 or fewer people does not have to enforce it, but the state says it still applies to every building, and meeting it is the owner's responsibility.

Do you need a permit to insulate here?

Woolwich publishes no answer either way. Insulation and air sealing appear on neither the permit-required list nor the exempt list. Woolwich's Planning Ordinance requires a building permit to erect a building over 200 square feet or to alter the bulk of any building; insulation inside an existing house is not named. 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 Woolwich

The published number is 207-295-4332. The department page is here.

Permitting is on us, not on you.

Rebates a Woolwich homeowner can actually use

55% of the occupied homes in Woolwich burn fuel oil or kerosene for heat, 4% use electricity and 11% propane or other tank gas (Census ACS 2020–2024). The insulation money for a Woolwich 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 Sagadahoc County can apply to Kennebec Valley Community Action Program (207-859-1500) for free weatherization through MaineHousing instead. Every condition is in the rebate guide. The Sagadahoc County page compares the towns.

Nearby

Woolwich borders Bath, Arrowsic, Georgetown, Bowdoinham, Dresden and Wiscasset. These are the ones we also cover, each with its own energy code and permit rule:

Elsewhere in Sagadahoc County we also cover:

How Woolwich 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 10 Sagadahoc County jurisdictions side by side →

Common questions about insulation in Woolwich

Code and permit facts checked October 24, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: woolwich.us (2, 3, 4) · cdn.townweb.com (2, 3, 4) · legislature.maine.gov · www2.census.gov · maine.gov · en.wikipedia.org (2, 3, 4) · zip-codes.com · efficiencymaine.com (2, 3, 4) · energystar.gov · data.census.gov. These change; confirm with the building department at 207-295-4332 or Efficiency Maine at 866-376-2463 first.