Connecticut

Insulation Contractors in Connecticut

The Home Insulators, a family-owned insulation company based in New Rochelle, NY, installs spray foam, blown-in cellulose and fiberglass, batts, rigid foam board and air sealing in houses across all eight Connecticut counties, from Greenwich and Stamford to Hartford, New London and Putnam, with our own 100-plus-person crew. We never subcontract. Most of our projects run between $3,500 and $12,500. Every Connecticut town is in climate zone 5A, and the state code in force asks R-60 of a new attic. Find your county and town below, or call 914-554-2289 for our free estimate.

Connecticut has 1,536,049 housing units, and 67.7% of them were built before 1980; 20.4% date from 1939 or earlier, and the median home was built in 1967, by the Census Bureau’s 2019–2023 American Community Survey. In that survey fuel oil heated 37.0% of the state’s occupied homes and utility gas 36.5%, close to a tie, with electricity at 17.8% and propane at 5.7%, and the oil share runs from 28.4% in Hartford County to 57.6% in Windham County. That split decides how the work pays: on oil and propane as fewer deliveries, on gas or electric heat as a smaller bill. 66.2% of occupied homes are lived in by their owners, and 58.7% of all units are detached houses.

Connecticut insulation contractors by county

Connecticut’s counties have existed only as geographical names since 1960, so each county page here simply groups its towns and covers their housing, gas companies and rebate details; each town page carries that town’s own figures. All the housing figures below come from the same 2019–2023 survey. Towns without a page of their own are served the same way and covered on their county page.

Fairfield County

379,899 housing units, 67.8% of them built before 1980. Utility gas heats 41.2% of occupied homes and oil 32.8%. United Illuminating serves Bridgeport, Stratford and Trumbull and shares Easton, Fairfield and Shelton with Eversource, which serves the rest; South Norwalk Electric and Water and the Third Taxing District serve parts of Norwalk. All 23 towns have a page:

Bethel · Bridgeport · Brookfield · Danbury · Darien · Easton · Fairfield · Greenwich · Monroe · New Canaan · New Fairfield · Newtown · Norwalk · Redding · Ridgefield · Shelton · Sherman · Stamford · Stratford · Trumbull · Weston · Westport · Wilton

Hartford County

388,186 housing units, 70.5% of them built before 1980, and the most gas-heated county in the state: utility gas 49.5%, oil 28.4%. Eversource delivers electricity in all 29 towns, and gas, where a town has it, comes from Connecticut Natural Gas or Eversource. 26 towns have their own page:

Avon · Berlin · Bloomfield · Bristol · Burlington · Canton · East Hartford · East Windsor · Enfield · Farmington · Glastonbury · Granby · Hartford · Manchester · New Britain · Newington · Plainville · Rocky Hill · Simsbury · South Windsor · Southington · Suffield · West Hartford · Wethersfield · Windsor · Windsor Locks

Litchfield County

87,727 housing units. 24.0% were built in 1939 or earlier, and 75.0% are detached houses, the highest share of the eight counties; oil heats 53.3% of occupied homes. Eversource serves all 26 towns, and more than half of them have no gas company. 9 towns have their own page:

Litchfield · New Hartford · New Milford · Plymouth · Thomaston · Torrington · Watertown · Winchester · Woodbury

Middlesex County

77,069 housing units. Oil heats 51.9% of occupied homes, and 24.5% of the housing went up in the 1980s and 90s. Eversource delivers electricity in all 15 towns. 12 towns have their own page:

Clinton · Cromwell · Durham · East Haddam · East Hampton · Essex · Haddam · Killingworth · Middletown · Old Saybrook · Portland · Westbrook

New Haven County

371,959 housing units, 70.0% of them built before 1980 and 22.8% in 1939 or earlier. Utility gas heats 40.7% of occupied homes and oil 33.5%. United Illuminating serves New Haven, East Haven, West Haven, North Haven, Orange, Milford, Ansonia and Derby and shares Hamden, Woodbridge and North Branford with Eversource; Eversource serves the rest, from Waterbury and Meriden to the shoreline towns of Branford, Guilford and Madison; and Wallingford has its own municipal electric company, which also serves part of North Branford. 26 towns have their own page:

Ansonia · Beacon Falls · Branford · Cheshire · Derby · East Haven · Guilford · Hamden · Madison · Meriden · Middlebury · Milford · Naugatuck · New Haven · North Branford · North Haven · Orange · Oxford · Prospect · Seymour · Southbury · Wallingford · Waterbury · West Haven · Wolcott · Woodbridge

New London County

122,712 housing units. Oil heats 50.8% of occupied homes and electricity 21.0%, the highest electric-heat share of the eight counties. Eversource serves most towns, while Groton Utilities, Norwich Public Utilities, Bozrah Light & Power and the Jewett City Department of Public Utilities serve their own areas and run their own efficiency programs. 12 towns have their own page:

Colchester · East Lyme · Griswold · Groton · Lebanon · Ledyard · Montville · New London · Norwich · Old Lyme · Stonington · Waterford

Tolland County

58,579 housing units, with the highest share built since 2000 of any county, 17.9%, and the lowest built before 1980, 57.2%. Oil heats 54.7% of occupied homes. Eversource serves all 13 towns. 8 towns have their own page:

Coventry · Ellington · Hebron · Mansfield · Somers · Stafford · Tolland · Vernon

Windham County

49,918 housing units, 26.0% of them built in 1939 or earlier, the highest share of the eight counties, and the most oil-dependent county: oil heats 57.6% of occupied homes. Eversource serves all 15 towns, and 9 have no gas company. 7 towns have their own page:

Brooklyn · Killingly · Plainfield · Putnam · Thompson · Windham · Woodstock

Insulation services in each Connecticut county

Each county also has its own page for six of our services, written with that county’s houses and code in mind:

The Connecticut houses we insulate, and where each one leaks

City two- and three-families. In New Haven 40.8% of the housing dates from 1939 or earlier and 23.5% of units sit in three- and four-unit buildings; in Hartford the figures are 38.5% and 23.0%, and Bridgeport, Waterbury and New Britain have the same kind of housing in somewhat smaller shares, 29.8% to 32.7% from 1939 or earlier and about 18% to 19% in three- and four-unit buildings. In the old wood-frame multifamilies the balloon-framed walls run open from cellar to attic, the stair hall rises the full height, and the top apartment sits under a shallow roof. We block the wall bays at the attic and cellar and seal the stair hall where it opens to the attic before any wall is filled, scope the building as one job, and check first for knob-and-tube wiring.

Capes and ranches of the 1940s and 50s. 20.7% of Connecticut’s housing went up in those two decades. The cape leaks behind its knee walls, where the floor bays run open to the eave; the ranch through a low attic of thin loose-fill, open at every top plate and light box. Both sit on a rim joist nobody sealed.

Raised ranches, splits and garrisons of the 1960s and 70s. 26.7% of the state’s homes come from those years, the largest group. They were insulated when new, so they get overlooked. The raised ranch loses heat at a bare rim above grade and through the garage ceiling under its bedrooms; the garrison at its overhang; the contemporary at cathedral slopes with batts pressed against the roof boards. Those rims, overhangs and slopes are where closed-cell spray foam does what a batt cannot.

Colonials of the 1980s and 90s. Those decades built 20.5% of the housing. Their walls are full; their heat goes overhead, through recessed lights, pull-down stairs, fireplace chases open to the attic, bonus rooms over the garage and ducts in a vented attic. If a newer house is already tight, we say so.

Antique houses and farmhouses. An eighteenth- or nineteenth-century timber frame has no regular stud cavities and relies on its walls drying out, so the work stays inside: the attic floor, the chimney and wall tops, and the cellar sill and rim, with no holes drilled in old clapboards. Our guide to insulating an older home goes through it.

Shore and lake cottages turned year-round. Many sit on crawl spaces or over open air, with floors that were never meant for winter. The dirt gets covered, then the floor above a vented crawl space or the walls of a sealed one get insulated; our crawl space guide and floor insulation guide lay out the choice.

In every one of them we seal before we insulate. Insulation slows heat passing through it; air moving through a gap carries heat straight around it. The air sealing comes first, at the top plates, chimney chase, attic hatch and rim joist, with baffles at the eaves, then the depth. Natural-draft furnaces, boilers and water heaters can backdraft in a tighter house, so any fuel-burning equipment should have its venting and combustion air checked before the house is tightened and tested again when the work is done; venting and combustion repairs are work for a heating contractor, and a combustion problem gets fixed before the sealing starts. If a quote specifies a depth of insulation and never mentions air sealing, it is half a job.

Spray foam insulation and everything else we install in Connecticut

We install open- and closed-cell spray foam, blown-in attic insulation, wall insulation, including dense-pack and injection foam in closed walls, basement walls and rim joists, crawl space encapsulation, cathedral ceilings and rooflines, the room over the garage, soundproofing insulation, new construction and removal of wet, failed or rodent-soiled insulation. Vermiculite is a separate matter: the EPA says to assume it contains asbestos and leave it undisturbed, and abatement is licensed work outside ours. So are mold remediation, waterproofing, heating equipment, electrical work and roofing.

Connecticut’s energy code, as of October 23, 2026

The code in force is the 2022 Connecticut State Building Code, which applies to projects with permit applications filed from October 1, 2022. It is based on the 2021 International Residential Code and the 2021 International Energy Conservation Code, with Connecticut amendments, the state Department of Administrative Services says.

The next code, based on the 2024 International Codes, was expected to take effect on July 1, 2026. The Department of Administrative Services says its effective date has been delayed while it awaits approval by the General Assembly’s Legislative Regulation Review Committee. That committee rejected the proposed 2026 building code without prejudice on December 16, 2025 and again on April 28, 2026, and it posted that it would not meet in October 2026, for lack of submissions. So the 2022 code still governs, and no date has been set for the next one. When it does take effect, it will apply to permits applied for after that date, with a code-modification grace period of about three months planned.

All of Connecticut is climate zone 5A: the 2021 IECC lists the state as “5A (all)”. Connecticut’s own design table uses one statewide row for most of its entries, among them a 7°F winter design temperature, a 42-inch frost line and “YES” for ice barrier underlayment, which the code requires at the eaves of new shingle roofs; ground snow loads and wind speeds are set town by town. Why the ice barrier matters is in our guide to ice dams.

On the code’s prescriptive path, the 2021 IECC table Connecticut uses calls for these in new homes and additions:

  • Ceilings: R-60, with R-49 accepted wherever its full, uncompressed height reaches over the wall top plate at the eaves.
  • Wood-frame walls: R-30 in the cavity, R-20 plus R-5 continuous, R-13 plus R-10 continuous, or R-20 continuous.
  • Floors: R-30. Basement and crawl space walls: R-15 continuous, R-19 in the cavity, or R-13 plus R-5 continuous. Slabs: R-10 to 4 feet.
  • Windows: U-0.30 or better, with a 0.40 maximum solar heat gain coefficient; skylights U-0.55.
  • Air leakage: under the code as Connecticut amended it, a new home must pass a blower-door test: no more than 3.0 air changes per hour at 50 pascals on the prescriptive path, and never more than 5.0 on any path. New wall, roof and floor assemblies in an addition are exempt from the test.

Existing houses are treated differently. The energy code does not require the unaltered parts of an existing home to be brought up to those numbers, and where ceiling, wall or floor cavities are opened during a project, filling them with insulation is accepted in place of new-construction levels, as long as the home’s energy use does not go up. Turning an unheated attic or garage into living space is different: the code treats it like an addition and requires the converted space to comply. Ask your town building department whether your project needs a permit. Our attic insulation guide gives ENERGY STAR’s recommended levels for an existing attic.

Energize CT rebates, in short

Insulation rebates in Connecticut run through Energize CT, which its own pages describe as an initiative of the Energy Efficiency Fund, the Connecticut Green Bank, the state and the local electric and gas utilities, paid for by a charge on customer energy bills. Customers of Eversource, United Illuminating, Connecticut Natural Gas and Southern Connecticut Gas start with a Home Energy Solutions visit: $40 for the standard tier since April 1, 2026, and no cost for the two income-based tiers. Energize CT’s insulation rebate page lists up to $2.00 per square foot or 75% of the cost, whichever is less, up to $10,000, for insulation the visit recommends, the program approves before work starts and a contractor in the Energize CT Insulation Installers Network installs. Spray foam is on its list of accepted materials, but Energize CT’s 2026 rebate terms say attic roof decks and rafters do not qualify. Homes whose electricity comes from a municipal utility, as in Norwich, Groton, Wallingford, Bozrah or parts of Norwalk, should check that utility’s own programs; a house on municipal electricity that buys gas from Eversource, Connecticut Natural Gas or Southern Connecticut Gas should ask the gas company whether it qualifies.

The professional-installation rebate is paid only on work by the network’s installers, and Energize CT’s Find a Participating Contractor tool lists them; Energize CT’s rebate page also lists $0.25 a square foot for self-installed insulation on an approved project, paid after an inspection. If the rebate matters most, book the Home Energy Solutions visit first and use a network contractor. If you want spray foam where the rebate does not reach, such as the underside of a roof deck, or would rather not wait for the program, we price the job on its own merits. The full rules, income limits, deadlines and financing are in our Energize CT insulation rebate guide. There is no federal homeowner tax credit for insulation installed in 2026; the insulation tax credit guide covers what 2025 work can still claim.

What insulation costs in Connecticut

Most of our projects run between $3,500 and $12,500. The house sets the number: a city two- or three-family is priced as one building, by its wall bays, stair hall and top-floor roof; a cape by its knee walls and eaves; a raised ranch by its exposed rim and the garage ceiling; a newer colonial by its attic, bonus room and ducts; a cottage by its crawl space and floors. The insulation cost guide and the spray foam cost guide break the numbers down by project.

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 is right in some assemblies and unnecessary in others; it costs more per inch, mainly because it uses more material. Code depth is where Connecticut differs: for a new home or addition its prescriptive table asks R-60 of an attic, about 22% more insulation than the R-49 in New Jersey’s 2024 and New York’s 2025 energy codes, though all three codes accept one step less where the full depth reaches over the wall top plates. ENERGY STAR says sealing air leaks and adding insulation can save up to 10% on annual energy bills.

Common questions about insulation in Connecticut

Do you install insulation everywhere in Connecticut?

Yes. We work in all eight counties, from Fairfield County to Windham County, with our own 100-plus-person crew and no subcontractors. 123 Connecticut towns have their own page on our website, grouped by county, and towns without a page are served the same way and covered on their county page.

How much does insulation cost in Connecticut?

Most of our projects run between $3,500 and $12,500. The house sets the price: a city two- or three-family is priced as one building, a cape by its knee walls and eaves, a raised ranch by its rim joist and garage ceiling, a newer colonial by its attic, bonus room and ducts. Closed-cell spray foam costs more per inch than open cell or blown-in. A written price follows our free estimate.

What R-value does Connecticut require for attic insulation?

For new homes and additions, the prescriptive requirement is R-60 in the ceiling under the 2021 International Energy Conservation Code as adopted in the 2022 Connecticut State Building Code, with R-49 accepted where its full, uncompressed height reaches over the wall top plate at the eaves. The code does not require the unaltered parts of an existing home to be brought up to that level. Energize CT’s rebate covers an attic floor only where the existing insulation is R-19 or less, and asks it to finish at R-49 or more, or R-38 where R-49 is not structurally practical.

What climate zone is Connecticut in?

Zone 5A, the whole state. The 2021 International Energy Conservation Code lists Connecticut as 5A in every county, and Connecticut’s own design table sets a 7°F winter design temperature, a 42-inch frost line and an ice barrier required at the eaves of new shingle roofs statewide.

Is Connecticut changing its energy code?

Not yet. As of October 23, 2026, the 2022 Connecticut State Building Code, based on the 2021 International Codes, still applies to permit applications filed since October 1, 2022. The next code, based on the 2024 codes, was expected on July 1, 2026, but the General Assembly’s Legislative Regulation Review Committee rejected it without prejudice in December 2025 and again in April 2026, and the committee posted that it would not meet in October 2026. No new date has been set.

Are there insulation rebates in Connecticut?

Yes, through Energize CT. Customers of Eversource, United Illuminating, Connecticut Natural Gas and Southern Connecticut Gas start with a Home Energy Solutions visit, $40 for the standard tier since April 1, 2026. Energize CT’s insulation rebate page lists up to $2.00 per square foot or 75% of the cost, whichever is less, up to $10,000, for insulation the visit recommends, the program approves first and a contractor in the Energize CT Insulation Installers Network installs. Its 2026 rebate terms say attic roof decks and rafters do not qualify. Homes on a municipal electric utility, such as Norwich Public Utilities, Groton Utilities or Wallingford’s electric division, should check that utility’s own programs; one that buys gas from Eversource, Connecticut Natural Gas or Southern Connecticut Gas should ask the gas company whether it qualifies.

Is there a tax credit for insulation in Connecticut in 2026?

Not for homeowners. The federal 25C credit is not allowed for property placed in service after December 31, 2025, and Connecticut’s 2025 income tax instructions list no insulation credit. Connecticut also ended its sales tax exemption for insulation and other residential weatherization products for sales on and after January 1, 2016.

Do you subcontract Connecticut jobs?

No. Every job is done by our own in-house crew of more than 100 people, the same crew that works in New York and New Jersey. The Home Insulators is family-owned and based in New Rochelle, NY, and has been insulating houses since 2015.

Free estimate in Connecticut

Our free estimate is our own walk-through, separate from Home Energy Solutions and not a route to a rebate. We look at the attic, its top plates and chimney chase; the knee walls in a cape; the rim joist and garage ceiling in a raised ranch; the wall bays and stair hall in a city multifamily; the crawl space or basement; and, wherever a furnace, boiler or water heater burns fuel, its venting and combustion air. You get the scope, the materials and depths, and the price in writing, with no obligation.

Call 914-554-2289, 8am–8pm, seven days, or use the contact form. The Home Insulators is family-owned, based in New Rochelle, NY since 2015, with a 100-plus-person in-house crew that never subcontracts. We also work across all of New Jersey, New York’s Hudson Valley and Long Island; see our service area.

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