The Home Insulators

Insulation Contractors in Hartford County, CT

Hartford County heats its houses two ways. Utility gas warms 49.5% of occupied homes and fuel oil or kerosene 28.4%, with electricity at 15.8%, but the county figure hides a split: oil heats 7.0% of homes in Hartford and 72.3% in Granby. In the city and the inner suburbs, sealing and insulating show up on a gas bill; toward the hills and the Massachusetts line, as fewer oil deliveries.

Of the county’s 388,186 housing units, 18.7% were built before 1940, 24.2% in the 1940s and 50s, 27.5% in the 1960s and 70s, 20.0% in the 1980s and 90s and 9.5% since 2000. Town medians run from 1953 in Hartford to 1981 in Avon and Burlington. 54.7% of units are detached houses, 6.5% townhouses or duplex halves, 7.4% in two-unit buildings and 9.7% in three- and four-unit buildings, and 64.5% of occupied homes are owner-occupied.

The Connecticut River splits the county into two unequal parts. Hartford, Windsor, Wethersfield and Farmington were among its towns in 1666, and Simsbury carried it to the Massachusetts border in 1670. West of the river sit the capital, the industrial cities of New Britain and Bristol, the inner suburbs and the Farmington Valley hill towns; East Hartford, Glastonbury and South Windsor hold the east bank. All but three of the 29 towns belong to the Capitol Planning Region. The 26 town pages carry the detail.

The Hartford County towns we work in

Each page carries that town’s own figures and gas company.

  • Avon — a 1981 median, the county’s newest with Burlington; oil 39.5%, gas 39.6%.
  • Berlin — Kensington and East Berlin: 20.6% from the 1950s, gas from CNG and Eversource.
  • Bloomfield — the old Wintonbury parish, a 1950s suburb where 18.5% of homes heat electrically.
  • Bristol — the clock-making city, where gas heats only 23.4%, oil 41.4% and electricity 27.4%.
  • Burlington — 88.7% detached, no buildings of twenty units or more, and 12.7% on propane.
  • Canton — Collinsville’s ax-factory village, 711 homes from the 2000s, and 52.6% on oil.
  • East Hartford — Pratt & Whitney’s town since 1929: 34.8% from the 1940s and 50s.
  • East Windsor — Warehouse Point and four more villages; 24.4% built since 2000, the most of the 26.
  • Enfield — Thompsonville’s carpet-mill housing and Green Manor’s winding roads; 49.0% on oil.
  • Farmington — Main Street colonials, 35.1% from the 1980s and 90s, and 41.0% on oil.
  • Glastonbury — Pyaug’s shipbuilding town: 154 houses from before 1800, 29.7% from the 1980s and 90s.
  • Granby — Salmon Brook and West Granby: oil heats 72.3% of homes, the most of the 26.
  • Hartford — the capital: 38.5% pre-1940, 23.0% of units in three- and four-unit buildings.
  • Manchester — the Cheney silk-mill town: 45.9% detached and 19.9% built before 1940.
  • New Britain — the Hardware City: 17.8% of units in two-unit and 18.9% in three- and four-unit buildings.
  • Newington — trolley suburb turned condominium town: 16.2% attached, the highest share of the 26.
  • Plainville — part of Farmington until 1869; oil 36.6%, gas 27.4%, electricity 27.1%.
  • Rocky Hill — Wethersfield’s old river port, with 24.1% of its homes built in the 1970s.
  • Simsbury — Talcott Mountain to the Tariffville Gorge: 39.1% from the 1960s and 70s, the most of the 26.
  • South Windsor — tobacco farmland turned suburb: 35.3% from the 1980s and 90s, the most of the 26.
  • Southington — an Interstate 84 bedroom town since the mid-1960s, with 1,811 units from the 2000s.
  • Suffield — incorporated in 1682 on the Massachusetts line; 87.2% owner-occupied, 20.6% since 2000.
  • West Hartford — trolley subdivisions and 1950s streets: 86.2% pre-1980, the highest share of the 26.
  • Wethersfield — Old Wethersfield’s 1,100 buildings and 30.8% from the 1940s and 50s.
  • Windsor — Connecticut’s first English settlement: 17.3% pre-1940 and two gas companies.
  • Windsor Locks — named for its 1829 canal locks, with 30.8% of homes from the 1950s.

The houses across Hartford County

Before 1940 the county built two kinds of house. In the cities it is the wood-frame two-, three- or four-family: Hartford is 38.5% pre-1940 with 23.0% of units in three- and four-unit buildings, and New Britain 29.8% pre-1940 with 18.9% in them. Balloon-framed walls stand empty from cellar to attic, the stair hall runs the full height, and the top apartment sits under a shallow roof. An owner on one floor decides for all of it, so we scope one building and check first for knob-and-tube wiring.

Elsewhere the old house is a single-family. West Hartford is 27.6% pre-1940, including the Colonial Revival and Tudor houses of 1920s West Hill, many with floored attics. Wethersfield, 22.0% pre-1940, holds Old Wethersfield’s 1,100 buildings, Glastonbury keeps 154 houses from before 1800, and Suffield and Farmington have historic Main Streets. An eighteenth-century timber frame has no regular stud cavities and relies on its walls drying out, so the work stays inside: the garret floor, the chimney and wall tops, the cellar sill and rim, and no holes in old clapboards.

The 1950s built 17.3% of the county, more than any later decade, mostly capes and ranches. Windsor Locks has 30.8% from that decade, Enfield 26.8%, West Hartford 25.4% and Wethersfield 24.6%. The cape leaks behind its knee walls, where 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.

The 1960s and 70s, 27.5%, are the largest era and the easiest to overlook, because those houses were insulated when new. Simsbury has 39.1% from them, Newington 38.7% and Rocky Hill 38.0%. The raised ranch loses heat at a bare rim above grade and through the garage ceiling under its bedrooms; the garrison colonial at its overhang; the 1970s contemporary at cathedral slopes whose batts lie tight against the roof boards. Those rims, overhangs and slopes are where closed-cell spray foam does what a batt cannot.

The 1980s and 90s lead in South Windsor at 35.3%, Farmington at 35.1% and Avon at 33.2%. Those colonials have full walls and lose heat overhead: recessed lights, pull-down stairs, fireplace chases open to the attic, bonus room floors and ducts in vented attics. Townhouses and duplex halves are 16.2% of Newington, where party walls often run open into an attic the association controls. If a newer house is already tight, we say so.

Fuel decides how the saving arrives. Oil leads in Canton at 52.6%, Simsbury at 50.5% and Enfield at 49.0%, and there sealing means fewer deliveries. Electricity heats 27.4% of homes in Bristol and 27.1% in Plainville, where the only way to cut that bill is to lose less heat. On the alluvial river flats, a damp basement gets its rim sealed, never foam on a wet wall.

We seal before we insulate

Insulation resists heat passing through it; air finding a gap carries heat straight around it. In a Hartford County house the gaps are open top plates, chimney and flue chases, the hatch or attic stair, the rim joist and, in older houses, wall bays open from cellar to attic.

In a raised ranch we start low: closed-cell foam on the above-grade rim and a sealed garage ceiling, then the attic plates, stack, fan ducts and hatch, the chimney chase closed with sheet metal and high-temperature sealant, baffles at the eaves, and only then depth. In a city two-family the balloon-frame bays are blocked at the attic and cellar and the stair hall is closed before a wall is filled. Where oil, propane or wood heats the house, we check the combustion air first.

If a quote specifies a depth of insulation and never mentions air sealing, it is half a job.

What insulation costs in Hartford County

Most of our projects run between $3,500 and $12,500. A city two- or three-family gets one price for the whole building, set 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 1980s colonial by its attic, bonus room and ducts. Spray foam insulation in Hartford and across the county goes where nothing else seals. The spray foam insulation cost guide breaks down the foam side.

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 Hartford County

Eversource delivers electricity in every Hartford County town. Connecticut Natural Gas (CNG) serves Avon, Bloomfield, Canton, East Hartford, Farmington, Glastonbury, Granby, Hartford, Manchester, New Britain, Newington, Rocky Hill, Simsbury, West Hartford and Wethersfield. Eversource gas serves Bristol, Burlington, East Granby, East Windsor, Enfield, Plainville, South Windsor, Southington, Suffield and Windsor Locks. Berlin and Windsor are split between the two; Eversource’s own list also names Farmington, which the state’s gas map shows as CNG; and Hartland and Marlborough have no gas company. The gas bill settles any doubt.

Home Energy Solutions is open to customers of Eversource, United Illuminating, Connecticut Natural Gas and Southern Connecticut Gas, whatever fuel heats the house. It suits homes of one to four units that have not had these services in the last six years, and renters need the landlord’s approval. An authorized contractor makes the visit for a $40 copay, effective 1 April 2026: health and safety tests, a blower-door test to pinpoint drafts and air leaks, a duct test for forced hot air or central air conditioning, and up to seven hours of air sealing at no cost, then $10 an hour. There may be a waiting list.

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, and spray foam is an accepted material. The insulation must be recommended during a Home Energy Solutions visit, approved before installation and installed by an approved contractor from the Energize CT Insulation Installers Network. Foam on the underside of a roof deck is not on the list, so ask the program before counting on a rebate for it.

For a household of three on Energize CT’s 2026–2027 figures, $78,692 or less is Income Eligible, with up to 100 percent coverage of insulation costs, and $78,693 to $104,924 is Enhanced Incentives, with a no-cost visit and up to $2.50 per square foot, a range that shifts by zip code. Every address in Bristol, East Hartford, Hartford and New Britain is in a state-designated environmental justice community, which can raise the incentive to $2.50 per square foot, up to $15,000. Parts of Bloomfield, East Windsor, Enfield, Farmington, Glastonbury, Manchester, Newington, Plainville, Rocky Hill, Simsbury, Southington, West Hartford, Wethersfield, Windsor and Windsor Locks are designated too; the state’s map shows whether an address qualifies.

The rebate is paid only on work by a network installer, so ask any installer, including us, whether they are in that network before you sign. For foam the rebate does not list, we price the job on its own merits. The Connecticut Green Bank’s Smart-E Loan finances insulation with no money down, up to $50,000, at 6.99% APR over 5, 7 or 10 years, 7.49% over 12 and 7.99% over 15 where the lender offers it, through participating contractors, so ask whether yours participates. Section 25C ended for anything placed in service after 31 December 2025, so there is no federal tax credit for insulation installed in 2026; be wary of anyone still advertising one. Our Connecticut rebate guide has the detail.

Code and climate in Hartford County

70.5% of Hartford County’s housing was built before 1980, from 86.2% of West Hartford down to 47.3% of Avon. Like all of Connecticut, the county is climate zone 5A, with a 7°F winter design temperature and a 42-inch frost line.

New homes and additions with applications filed since 1 October 2022 follow the 2022 Connecticut State Building Code, which adopts the 2021 IECC with state amendments: R-60 ceilings, with R-49 accepted where its full, uncompressed height reaches over the wall top plate at the eaves; wood-frame walls of R-30 cavity, R-20 plus R-5 continuous, R-13 plus R-10 continuous or R-20 continuous; R-30 floors; basement walls of R-15 continuous, R-19 cavity or R-13 plus R-5 continuous; and U-0.30 windows. A new home must pass a blower-door test at 3.0 air changes per hour at 50 pascals on the prescriptive path, and never worse than 5.0. Connecticut’s next code, based on the 2024 IECC, has been adopted in draft, but its effective date has been delayed.

Common questions about insulation in Hartford County

Do you install insulation in Hartford County, CT?

Yes. We insulate houses in all 29 towns, East Granby, Hartland and Marlborough included: owner-lived two- to four-families in Hartford, New Britain and Bristol; pre-war colonials and Tudors in West Hartford and Wethersfield; capes and ranches in East Hartford, Enfield and Windsor Locks; raised ranches in Newington, Rocky Hill and Simsbury; and 1980s colonials and townhouses in South Windsor, Farmington and Avon. Apartment and condominium buildings of five or more units belong to their owners or boards, so that work starts with them.

How much does insulation cost in Hartford County?

Most projects run $3,500 to $12,500. In the cities, a two- or three-family is quoted as a single job, driven by its balloon-framed wall bays, stair hall and the roof over the top apartment. A cape turns on its knee walls and eaves, a raised ranch on the above-grade rim and garage ceiling, and a 1980s colonial on the attic, the bonus room and any ducts up there. Closed-cell spray foam on rims, overhangs and cathedral slopes costs more per inch. A written price follows a free walk-through.

Are there insulation rebates in Hartford County?

Yes, through Energize Connecticut. An Eversource or CNG account opens a Home Energy Solutions visit, $40 on the standard tier. Insulation recommended at that visit, approved first and installed by an Energize CT Insulation Installers Network contractor can earn up to $2.00 per square foot or 75 percent of cost, whichever is less, to $10,000. Every address in Hartford, New Britain, East Hartford and Bristol, and some in fifteen other towns, sits in an environmental justice community, where the incentive can reach $2.50 per square foot. No federal tax credit applies in 2026.

Which utility do I have in Hartford County?

Eversource supplies electricity in all 29 towns. For gas, Connecticut Natural Gas (CNG) serves Avon, Bloomfield, Canton, East Hartford, Farmington, Glastonbury, Granby, Hartford, Manchester, New Britain, Newington, Rocky Hill, Simsbury, West Hartford and Wethersfield. Eversource gas serves Bristol, Burlington, East Granby, East Windsor, Enfield, Plainville, South Windsor, Southington, Suffield and Windsor Locks. Berlin and Windsor are split between the two, and Hartland and Marlborough have no gas company. The name on your bill settles it.

Free estimate in Hartford County

Our free estimate is our own walk-through, apart from Home Energy Solutions and no route to a rebate. In a city multifamily we check the roof over the top apartment, the stair hall, the tops of the wall bays and the cellar rim; in a cape, the knee-wall attics; in a raised ranch, the rim and garage ceiling; on oil or propane, the combustion air. You get the scope and the price in writing, free and with no obligation.

Call 914-825-6824, 8am–8pm, seven days, or send the contact form. We work from New Rochelle, NY, with a 100-plus in-house crew and no subcontractors.

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Insulation services in Hartford County, CT