The Home Insulators

Insulation Contractors in Suffolk County, NY

Fuel oil heats 44.9% of Suffolk County’s occupied homes and utility gas 41.0%, with electricity at 8.6% and bottled gas at 3.7%; next door in Nassau, gas leads by a wide margin. Oil runs from 86.1% of homes in Mastic down to 13.3% in Melville. Where heat comes by truck, sealing and insulating pay back as fewer deliveries each winter.

The county has 579,790 housing units, and the median one dates from 1970. 37.6% went up in the 1960s and 70s, 21.9% in the 1940s and 50s and 19.2% in the 1980s and 90s; 12.1% have been built since 2000 and 9.2% predate 1940. 79.9% are single-family detached houses, 5.8% townhouses or duplex halves and 1.3% mobile homes, and 81.9% of occupied homes are owner-occupied.

The South Shore places face the Great South Bay on flat outwash plain, from Lindenhurst and Babylon to Patchogue, with Mastic Beach farther east on Moriches Bay. The North Shore is hillier, from Fort Salonga and Kings Park to Stony Brook, Mount Sinai and Wading River. Between them the Ronkonkoma Moraine rises at Bald Hill in Farmingville, and the Long Island Central Pine Barrens take in parts of Ridge, Manorville and Medford. Riverhead, the county seat, stands where the North and South Forks split, though most county offices moved west to Hauppauge. The 54 place pages carry the detail.

The Suffolk County places we work in

Most are hamlets with no government of their own; Babylon, Lindenhurst and Patchogue are villages. Each sits under its Town.

Town of Babylon

  • Babylon — the village: 65.8% gas heat, 6.0% in three- and four-unit buildings.
  • Copiague — 68.6% gas heat, 35.4% built in the 1940s–50s.
  • Deer Park — farms until the post-war boom; 42.9% from the 1960s–70s.
  • Lindenhurst — the village: 42.5% from the 1940s–50s, 55.1% gas heat.
  • North Amityville — 16.0% of units in buildings of 50 or more.
  • North Babylon — 45.4% from the 1940s–50s and 54.2% gas heat.
  • North Lindenhurst — 43.9% built in the 1940s–50s, just 2.9% since 2000.
  • West Babylon — 14,456 housing units, second only to Coram; 38.8% from the 1940s–50s.

Town of Brookhaven

  • Centereach — Dawn Estates began in the early 1950s; 39.3% oil heat.
  • Coram — 16,235 housing units, the most of the 54.
  • East Patchogue — on the Swan River: 14.4% built before 1940.
  • East Setauket — 3.1% mobile homes and 24.3% built in the 1980s–90s.
  • Farmingville — 91.8% detached, 28.3% built in the 1970s, 16.1% gas heat.
  • Holtsville — mostly Brookhaven, part Islip: 25.9% from the 1980s–90s.
  • Lake Ronkonkoma — beside the lake: 28.5% from the 1940s–50s, 11.6% since 2000.
  • Manorville — 19.7% built before 1980, the smallest share of the 54.
  • Mastic — once called Forge: 23.1% from the 1980s–90s, 14.9% since 2000.
  • Mastic Beach — 96.4% detached; 2.0% gas heat, the least of the 54.
  • Medford — Eagle Estates dates from 1963; 60.2% from the 1960s–70s.
  • Miller Place — beach cottages turned family homes; 28.7% from the 1980s–90s.
  • Mount Sinai — 38.4% built since 2000, the most of the 54.
  • Patchogue — the village: 49.7% detached and 56.0% owner-occupied, both the lowest.
  • Ridge — the Gateway to the Pine Barrens: 33.0% from the 1980s–90s.
  • Rocky Point — North Shore hamlet: 93.9% detached, 29.5% from the 1940s–50s.
  • Selden — Nature’s Gardens lots from 1931, then 58.3% from the 1960s–70s.
  • Shirley — Walter T. Shirley’s four-room houses; 3.1% wood heat, the most of the 54.
  • Stony Brook — beside the university campus: 89.3% detached, 49.6% oil heat.

Town of Huntington

  • Dix Hills — farmland until after World War II; 96.8% owner-occupied.
  • East Northport — 89.0% built before 1980, 42.4% from the 1940s–50s.
  • Elwood — 57.5% gas heat, 90.6% detached, 9.2% built since 2000.
  • Fort Salonga — the old Gold Coast’s eastern edge: 97.9% owner-occupied, the most of the 54.
  • Greenlawn — 84.0% built before 1980; 48.9% gas, 11.2% electric heat.
  • Huntington — the hamlet around Huntington Village: 39.1% from the 1940s–50s.
  • Huntington Station — once called Fairground: 6.6% of units in two-unit buildings.
  • Melville — median 1985; 76.1% gas heat, the most of the 54.
  • South Huntington — 52.5% from the 1940s–50s, the most of the 54.

Town of Islip

  • Bay Shore — Fire Island ferry terminals: 15.7% electric heat, 14.1% built since 2000.
  • Central Islip — 10,660 housing units; 27.2% from the 1940s–50s, 51.9% gas.
  • East Islip — near Heckscher State Park: 16.9% built before 1940.
  • Holbrook — mostly Islip, part Brookhaven: 58.0% from the 1960s–70s.
  • Islip — the hamlet, not the Town: 45.5% from the 1960s–70s.
  • North Bay Shore — once farms; 10.1% propane heat, the most of the 54.
  • Ronkonkoma — home of MacArthur Airport: 10.1% built before 1940.
  • Sayville — grand homes of 1880 to 1930; 34.4% from the 1960s–70s.
  • West Islip — Sampawams Creek to the bay: 96.2% detached, 95.8% owner-occupied.

Town of Riverhead

  • Riverhead — the county seat: 7.3% mobile homes, the most of the 54.
  • Wading River — once cottages on the cliffs and dunes; 5.0% mobile homes.

Town of Smithtown

  • Commack — mostly Smithtown, part Huntington: 11,915 units, 93.7% owner-occupied.
  • Hauppauge — where most county offices moved: 60.4% from the 1960s–70s.
  • Kings Park — by Sunken Meadow: 52.3% from the 1960s–70s, 50.3% gas.
  • Nesconset — 52.5% oil heat, 22.6% built in the 1980s–90s.
  • Smithtown — takes in the former Village of The Landing; 37.8% built in the 1960s.
  • St. James — south of Stony Brook Harbor: 11.1% townhouses, 43.0% gas heat.

Town of Southampton

  • Hampton Bays — settled as Good Ground in 1740; 9.3% propane, 14.4% gas.

The houses across Suffolk County

Western Suffolk filled in first. After World War II the farms of Deer Park, Dix Hills and East Northport became subdivisions, and the 1940s and 50s are 52.5% of South Huntington’s housing, 45.4% of North Babylon’s and 44.2% of West Islip’s: capes and ranches. A cape’s upstairs sits inside three small attics, the space behind each knee wall, the joist bays running open under the bedroom floor to the eave, and a shallow flat attic above. A ranch has one long attic, its loose-fill sunk low over the years.

Suffolk’s biggest cohort, the 1960s and 70s, built high ranches and split-levels: 60.8% of Dix Hills, 60.4% of Hauppauge and 58.3% of Selden, with 43.5% of Commack from the 1960s alone. A high ranch leaks at the rim joist of its half-buried lower level, at the garage ceiling under a bedroom and at the cantilevered overhang. A split leaks where its attic meets the bare framing of the taller wing.

The oldest houses are in the villages and older hamlets: 27.9% of the Village of Babylon predates 1940, as do 24.9% of Patchogue, 23.8% of Huntington and 19.8% of Sayville, which built grand homes and estates between 1880 and 1930; Islip keeps many Queen Anne Revival houses. Expect balloon framing, plaster and wiring to check before a wall is filled. Babylon and Lindenhurst took floodwater in Hurricane Sandy, and a basement that has flooded gets its insulation in the floor framing above it.

Brookhaven built later. Medford is 41.7% from the 1970s and Coram 35.1%; Ridge is 33.0% from the 1980s and 90s and Manorville 54.5%, the most of the 54. In Ridge the Longwood Estate was carved into housing developments after 1967, and townhouses are now 22.8% of Ridge. These raised ranches, colonials and townhouse rows have batts in the walls and lose heat through the attic plane, attic ducts and the bonus room over the garage; where an association owns the roof, it decides on work there.

Houses built since 2000 cluster in a few places: 38.4% of Mount Sinai, where the 404-acre Davis Peach Farm was developed in the early 2000s, 36.6% of the hamlet of Riverhead and 35.8% of Melville, which is also 23.2% townhouses. Those walls met the code of their day; the work is the two-story foyer, attic ductwork and the party wall between attics.

Along the water, summer places became homes. Many of Lake Ronkonkoma’s resort-era cottages and bungalows now serve year-round, most of Miller Place’s beach cottages became family homes after World War II, and most of Shirley’s early-1900s Tangiers-era bungalows still stand. A cottage built for July sits over a crawl space or piers, with shallow rafters, unfilled walls and additions from several decades. These are the oil places too: 86.1% of Mastic, 85.3% of Mastic Beach, 79.6% of Shirley and 77.2% of Rocky Point, all with little or no utility gas service.

Mobile homes reach 7.3% of Riverhead and 5.0% of Wading River, losing heat through torn belly wrap and loose ducts. Two-family houses are 15.2% of North Lindenhurst and 11.3% of Lindenhurst, each scoped as one building with the floor between units. North Amityville has 16.0% of its units in buildings of 50 or more; for those, and for condominium complexes and campuses, the owner, board or association decides on work to the roof and exterior walls.

We seal before we insulate

A blanket of insulation resists heat passing through a ceiling or wall, but warm air still slips out through gaps up high and pulls cold air in low.

In Suffolk’s most common house, a 1960s or 70s high ranch, the order is: seal the rim joist along the lower level and the garage ceiling beneath the bedrooms; from the attic, seal the top plates, wire and pipe holes, the hatch, bath fans and recessed lights; close the gap around the oil boiler’s chimney with metal flashing and fire-rated caulk; then add depth. In a converted cottage, the floor over the crawl space comes first.

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

What insulation costs in Suffolk County

Most of our projects run between $3,500 and $12,500. The number follows the house: a cape’s knee walls against a ranch’s single attic, a high ranch’s rim and garage ceiling, a newer colonial’s attic ducts, a converted cottage’s crawl space. Spray foam goes where it earns its price, at rim joists, cathedral slopes and floors over open crawl spaces; see what spray foam insulation costs.

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 Suffolk County

PSEG Long Island supplies the electricity in all 54 places on the list, and New York ties a home’s insulation programs to its electric company. Elsewhere in the county, the Village of Greenport has its own village-owned electric system, and Fishers Island is served by the Fishers Island Electric Corporation.

Gas comes only from National Grid, and it thins out going east. Most of Melville, Commack, Dix Hills, Elwood, South Huntington and the villages of Babylon and Lindenhurst are on its lines. Gas lines reach only parts of Farmingville, Holtsville, Medford, Miller Place, Nesconset, Ronkonkoma, Wading River and Hampton Bays, and Mastic, Mastic Beach, Rocky Point and Shirley have little or no utility gas service. Elsewhere on the list, gas runs on many streets but not every street.

PSEG Long Island lists a $2,500 insulation rebate and a $1,000 air-sealing rebate for market-rate single-family homes, with higher amounts for income-qualified homes and homes in state-designated disadvantaged communities, paid through its participating contractors after a free Whole House Energy Assessment that includes a thermal scan and a blower door test. Insulation must go in with comprehensive, blower door assisted air sealing, and ductwork in unconditioned space must be sealed. NYSERDA’s Comfort Home packages are not open to PSEG Long Island customers.

NYSERDA’s EmPower+ serves income-eligible owners and renters in their primary residence. In Suffolk, a four-person household earning $98,925 or less can get air sealing and insulation at no cost up to $14,000; one earning under $131,900 can get half the cost covered up to $7,000. Payment runs through an EmPower+ contractor, and the program’s federal HEAR funds add up to $1,600 more. National Grid’s Long Island insulation rebate program is not taking new applications. Check eligibility on the MyEnergy portal, and in Greenport check with your village electric department too.

NYSERDA’s Green Jobs–Green New York program lends $1,500 to $25,000 over 5, 10 or 15 years. The federal insulation tax credit (Section 25C) ended for work placed in service after 31 December 2025, so there is no federal insulation credit on a 2026 job, and New York has no state tax credit for insulation. Amounts and rules for each are collected in the insulation rebates guide.

Code and climate in Suffolk County

Lindenhurst has 89.1% of its housing built before 1980, Manorville only 19.7%, and the county as a whole 68.7%. New York’s first statewide energy code took effect on 1 January 1979; most Suffolk houses were framed before any state energy rule existed. Suffolk County is Climate Zone 4.

New houses have been built since 31 December 2025 to the 2025 Energy Conservation Construction Code of New York State. For Zone 4 it sets R-49 ceilings, with R-38 accepted where it covers the whole ceiling at full, uncompressed height over the wall top plate at the eaves; R-30 floors; R-15 continuous, R-19, or R-13 plus R-5 continuous on basement and crawl space walls; U-0.27 windows; and air leakage no higher than 3.0 air changes per hour at 50 pascals.

When an existing house is insulated, unaltered portions need not comply, New York’s code does not require a blower door test when you insulate an existing home, and cavities the work exposes get insulated to full depth. PSEG Long Island’s rebate rules go further and call for blower door assisted air sealing. ENERGY STAR’s attic advice for Zone 4 is R-60 if the attic is uninsulated and R-49 if it already has 3 to 4 inches.

Common questions about insulation in Suffolk County

Do you install insulation in Suffolk County, NY?

Yes, in the 54 places listed above, from Lindenhurst, Babylon and Bay Shore on the Great South Bay to Commack, Hauppauge and Stony Brook, and east through Brookhaven to Riverhead and Hampton Bays. The houses run from pre-war village houses and post-war capes to high ranches, newer colonials, townhouses and cottages made year-round. For a condominium or apartment building, the owner, board or association decides on work to its roof and exterior walls.

How much does insulation cost in Suffolk County?

Most projects run $3,500 to $12,500. A cape costs more than a ranch of the same size because its knee walls, slopes and eave bays all need work; a high ranch adds its rim joist and garage ceiling, a newer colonial its attic ducts, a converted cottage its crawl space. Closed-cell foam costs more per inch than open cell, so we save it for rim joists, shallow slopes and damp crawl spaces. Our visit and quote cost nothing.

Are there insulation rebates in Suffolk County?

Yes, through PSEG Long Island, which lists a $2,500 insulation rebate and a $1,000 air-sealing rebate for market-rate single-family homes, more for income-qualified homes, paid through its participating contractors after a free Whole House Energy Assessment. Income-eligible owners and renters can apply to NYSERDA’s EmPower+. Comfort Home is not available to PSEG Long Island customers, and the federal 25C credit ended for work placed in service after 31 December 2025.

Which utility do I have in Suffolk County?

Electricity is PSEG Long Island almost everywhere; the Village of Greenport has its own village-owned electric system, and Fishers Island has the Fishers Island Electric Corporation. Gas is National Grid’s where it exists: most of Melville, Commack, Dix Hills and the villages of Babylon and Lindenhurst, only parts of Medford, Farmingville and Hampton Bays, and little or none in Mastic, Mastic Beach, Rocky Point and Shirley. Your bill settles it.

Free energy audit in Suffolk County

We start low, at the crawl space or lower level, rim joist and garage ceiling, then the knee walls, then the attic, where we gauge the depth and trace the holes through the ceiling below. In an oil-heated house we check the boiler’s combustion air and the chimney before tightening anything. The scope and price come to you in writing, and neither costs anything.

Phone 914-825-6824 or send a message. We answer 8am–8pm, seven days, from New Rochelle, NY, and our own 100-plus in-house crew does the work; we never subcontract.

Learn more

Insulation services in Suffolk County, NY