Four decades built most of Durham. The 1960s added 17.2% of today’s 3,080 housing units, the 1970s 18.4%, the 1980s 14.5% and the 1990s 18.5%, a steady build-out with no single boom. That makes Durham four kinds of attic in one town, and the right work in a 1962 ranch is not the right work in a 1996 colonial on the next road.
93.7% of units are detached houses, 91.8% of occupied homes are owner-occupied, and just 42 units were counted vacant: Durham is lived in all year. The median unit dates from 1976. Fuel oil heats 74.8% of occupied homes, electricity 9.6%, bottled gas 7.1%, wood 4.5% and utility gas 2.6%, and solar is the main heating fuel in 1.4%. For the oil majority, a tighter house means fewer deliveries and a boiler that runs less, and those savings repeat every heating season for as long as the house burns oil.
The houses we insulate in Durham
The 1960s ranch. 529 homes date from that decade. A ranch of that age has a long attic over a ceiling full of penetrations: light boxes, a plumbing vent, the hatch, and the tops of every interior wall, each open to the attic above. The original fiberglass is usually a few inches deep and now matted down. Adding more on top without sealing those openings first leaves the leaks in place under a thicker blanket.
The 1970s raised ranch and split-level. 568 homes. The raised ranch puts living space over a garage and wraps a rim joist around a lower level that is half in the ground and half out. The split-level stacks attics at two heights and leaves a short wall between them, often open framing that lets the lower attic breathe into the upper one. Both types often have their oil boiler on the lower level, next to the rim joist that needs foam.
The 1980s contemporary and colonial. 448 homes. The contemporaries brought cathedral ceilings, skylights and tall glass walls; the colonials added bonus rooms over garages. Walls went up with batts, so the losses are at the ceilings. A cathedral ceiling packed with fiberglass against the roof deck, with no vent space, often shows up as ice along the eaves in a cold snap.
The 1990s colonial. 569 homes, the largest single decade. A colonial of that era typically has two stories, a two-story foyer or family room, a bonus room over a two- or three-car garage, recessed lights in every room and, often, a central air handler and its ductwork in the attic. The attic floor is insulated. The air handler, the ducts, the knee walls of the bonus room and the tall walls of the foyer are where the heat and the cooling go.
Then there is the solar roof. In the homes that heat with solar, and in any house with panels, conduit and mounting hardware pass through the roof into the attic. Those holes are sealed like any other penetration before insulation covers them.
Main Street and the farm town before it
Durham was a farming village on the Coginchaug River, settled on land bought from the Mattabesset (Wangunk) around 1662 and incorporated in 1708. It still hosts the Durham Fair every autumn, the largest volunteer agricultural fair in New England. The core of the town center is the Main Street Historic District, on the National Register and noted for the architecture of its houses, and the Elias Austin House and Thomas Lyman House are among the town’s historic locations. The Metacomet Ridge, with Trimountain, Fowler Mountain and Pistapaug Mountain, rises along the west side of town.
Only 9.3% of Durham’s homes, 286 of them, were built before 1940, and they call for the most care. A house of that age on or near Main Street may have a timber frame with walls that are empty or filled with brick, a chimney mass with open gaps beside it at each floor, and an attic floor of loose boards over lath and plaster. It may also have a barn, shed or kitchen ell joined to it at some point, with its own roof and its own gaps.
The work in a house like that is conservative. The attic floor gets sealed and insulated first, because that is where the most heat leaves and nothing visible changes. The chimney gaps are closed with sheet metal. Walls are opened only with a small inspection hole, and filled only if they have a cavity, no knob-and-tube wiring and a way to dry.
We seal before we insulate
Air moving through a gap carries far more heat than the same gap would lose by conduction, and insulation piled over the gap does not stop the air. Seal first, then insulate, and check the result.
In a 1990s Durham colonial the sequence is: seal the attic hatch and the gaps around the air handler’s platform; seal every duct joint and boot in the attic with mastic; box and seal the recessed lights; seal the top of the two-story foyer wall where it meets the attic; air-seal and insulate the bonus room’s knee walls and the floor cavity beneath it; baffle the eaves; then blow the attic to depth.
If a quote specifies a depth of insulation and never mentions air sealing, it is half a job.
What insulation costs in Durham
Most of our projects run between $3,500 and $12,500. A 1960s ranch is priced on its attic area and how many penetrations need sealing. A 1970s raised ranch adds the garage ceiling and the lower-level rim. A 1980s contemporary depends on whether its cathedral ceilings can be reached. A 1990s colonial is priced on the attic ductwork, the bonus room and the foyer wall, and a pre-1940 house on Main Street on what its attic and walls will safely take.
Open cell foam runs R-3.9 to R-4.2 per inch. Closed cell runs R-6.9 to R-7.1 per inch and also acts as a vapor retarder, which is why it costs more and why it is right in some assemblies and unnecessary in others. All products are manufactured in the United States and meet applicable building code and safety standards. ENERGY STAR says sealing air leaks and adding insulation can save up to 10% on annual energy bills.
Insulation rebates in Durham
Eversource is Durham’s electric company and also its gas company. Home Energy Solutions is open to customers of Eversource, United Illuminating, Connecticut Natural Gas and Southern Connecticut Gas, and with utility gas in 2.6% of homes, most Durham households will sign up through their electric account. The fuel that heats the house does not matter. The program serves homes of one to four units, and a home that had these services in the last six years has to wait.
Since 1 April 2026 the standard Home Energy Solutions visit has carried a $40 copay. The program’s authorized contractor does health and safety tests, a blower-door test to pinpoint drafts and air leaks, and a duct test where the house has forced hot air or central air conditioning, which describes many 1990s colonials. Air sealing costs nothing for up to seven hours, then $10 an hour. The visit ends with a report on the blower-door results and recommended upgrades, with rebate and financing details. There may be a waiting list, and funding is limited to what the program has available.
The 2026 Energize CT insulation rebate pays up to $2.00 per square foot or 75 percent of the total cost, whichever is less, to a maximum of $10,000, on attic floors, floored-over attics, walls, basement and garage ceilings and rim joists. To qualify, an attic floor at R-19 or less must be brought to R-49 or more, unless the attic structurally cannot take it, in which case R-38 is the minimum. Foam on the underside of a roof deck is not listed; ask the program before counting on a rebate for it. The insulation must first be recommended during a Home Energy Solutions visit, then approved before installation, then installed by an approved contractor from the Energize CT Insulation Installers Network. Self-installed insulation earns $0.25 per square foot and must be inspected before that rebate is paid.
Energize CT sorts households into three tiers by income, using its 2026–2027 figures. Three people earning $78,692 or less land in Income Eligible: no charge for the visit, and coverage of insulation costs up to 100 percent. Earning $78,693 to $104,924 puts them in Enhanced Incentives: again no charge for the visit, plus as much as $2.50 per square foot for insulation, within limits that vary by zip code. At $104,925 or more the standard tier applies. Assets such as the house and car are not counted for the Income Eligible tier. Near a limit, ask which tier fits before paying the copay.
The rebate goes only to work done by network installers, so ask any installer, including us, whether they are in the network before you sign. Durham owners who would rather spread the cost can look at the Connecticut Green Bank’s Smart-E Loan. It asks no money down, lends as much as $50,000 and charges 6.99% APR on a 5-, 7- or 10-year term, 7.49% on 12 years and 7.99% on 15, a term only some lenders offer. The house must be owner-occupied with one to four units, and only the Green Bank’s participating contractors can put a project through, so ask whether yours does. A 2026 insulation job carries no federal tax credit; Section 25C ended for property placed in service after 31 December 2025. Our Connecticut rebate guide covers the details.
Code and climate in Durham
57.7% of Durham’s housing was built before 1980. Durham is in climate zone 5A, the zone for all of Connecticut. The 2022 Connecticut State Building Code, which is the 2021 IECC with state amendments, governs applications filed on or after 1 October 2022.
New homes and additions in Durham are built to these values:
- Ceilings: R-60, or R-49 where its full uncompressed depth carries over the wall top plate at the eaves
- Wood-frame walls: R-30 cavity; R-20 cavity plus R-5 continuous; R-13 cavity plus R-10 continuous; or R-20 continuous
- Floors: R-30
- Basement walls: R-15 continuous, R-19 cavity, or R-13 cavity plus R-5 continuous
- Windows: U-0.30
- Air leakage: a blower-door result of 3.0 air changes per hour at 50 pascals on the prescriptive path, and never worse than 5.0
Connecticut’s next edition, drawn from the 2024 IECC, has been adopted in draft; its effective date has been delayed.
Common questions about insulation in Durham
Do you install insulation in Durham, CT?
Yes, throughout Durham: 1960s ranches, 1970s raised ranches and split-levels, 1980s contemporaries and colonials, the large 1990s colonials that make up the biggest single decade in town, and the older houses in and around the Main Street Historic District. The work differs by decade, from sealing a ranch ceiling to sealing attic ductwork in a 1990s colonial, and we plan each house by its age and layout rather than by a standard package.
How much does insulation cost in Durham?
Most projects run $3,500 to $12,500. A 1960s ranch depends mainly on attic area and the penetrations to seal. A raised ranch adds the garage ceiling and lower-level rim, and a contemporary depends on access to its cathedral ceilings. A 1990s colonial is priced on its attic ductwork, bonus room and foyer wall. A Main Street house depends on what its attic and walls can safely take. The walk-through is free, and the scope and price are written down.
Are there insulation rebates in Durham?
Yes, through Energize Connecticut. Durham’s electricity and gas both come from Eversource, and heating oil does not rule a house out. A Home Energy Solutions visit comes first, at a $40 copay on the standard tier. After it, insulation the visit recommended can earn up to $2.00 per square foot or 75 percent of the total cost, whichever is less, with a $10,000 cap, provided the program approves it before installation and an Energize CT Insulation Installers Network contractor installs it. No federal tax credit applies to 2026 installations.
Our 1960s Durham ranch still has its original attic insulation. Is adding more enough?
Not by itself. The original layer is thin, but the bigger loss is usually air rising through the ceiling: around light boxes, the plumbing vent, the hatch and the top plates of interior walls. Blow new insulation over those gaps and warm, moist air keeps moving into the attic underneath it. We seal the penetrations first, check the bath fan vents actually reach outdoors, add baffles at the eaves, and then bring the attic up to depth.
Free estimate in Durham
We start a Durham walk-through by dating the house, because the decade tells us where to look. In a ranch, the attic ceiling and its penetrations; in a raised ranch, the garage ceiling and the rim beside the boiler; in a 1990s colonial, the attic ductwork, the bonus room and the foyer wall; on Main Street, the attic floor and the chimney. You get a written scope and a price, at no charge. It is our free estimate, separate from the Home Energy Solutions visit, and it does not qualify a house for a rebate.
Call 914-825-6824, answered 8am–8pm seven days a week, or use the contact form. We are a New Rochelle, NY company, and the work is done by our 100-plus in-house crew, never by subcontractors.
Learn more
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