89.1% of Lindenhurst’s 9,069 homes were built before 1980. 17.0% predate 1940, 12.0% come from the 1940s and 30.5% from the 1950s, and the median home dates from 1957. 81.2% are detached houses, 11.3%, or 1,029 homes, are in two-unit buildings, and 85.2% of occupied homes are lived in by their owners.
Lindenhurst is an incorporated village inside the Town of Babylon, on the South Shore between Copiague and West Babylon, with North Lindenhurst above it and the Great South Bay below. 55.1% of occupied homes heat with utility gas and 39.8% with fuel oil. PSEG Long Island supplies the electricity, and most of the village is on National Grid gas lines. One event shapes insulation work here as much as any number: on 30 October 2012 Hurricane Sandy flooded over half the village’s streets, and south of Montauk Highway the water reached up to six feet.
The houses we insulate in Lindenhurst
German settlers from Breslau in Silesia founded the community in 1873 and named it after their city; it became Lindenhurst in 1891, voted to incorporate as a village in 1923 and marked its centennial in 2023. The oldest layer of housing is 1,539 homes built before 1940. In those we expect walls with no insulation, balloon framing in the taller houses, a cramped attic reached through a closet ceiling, and a cellar where the wood sill rests unevenly on an old foundation with gaps along its length. The sill and the rim get sealed, the wall cavities get blocked at the top and bottom before they are dense-packed, and any knob-and-tube wiring is replaced before a wall is filled.
42.5% of the stock comes from the 1940s and 50s, the capes and small ranches that make up the bulk of the village. A post-war cape here has three separate insulation problems stacked on top of each other: a first floor over a basement whose rim joist was never touched, bedrooms upstairs behind knee walls with open floor bays running to the eave, and a flat attic at the peak so small that the insulation in it has been walked on and pushed aside every time someone ran a cable. The ranch is simpler, one low attic, but the loose-fill in it has settled to a few inches and thins to nothing at the eaves.
The 1960s and 70s added 29.6%, mostly high ranches and splits with a garage under a bedroom and a lower level partly below grade. Their weak points are the garage ceiling, the rim joist around the lower level and the long attic above. Since 1980 the village has added little: 5.3% in the 1980s and 90s and 5.6% since 2000.
Then the two-family houses, 1,029 of them. A Lindenhurst two-family is usually a house with a second apartment, one unit over the other or one beside the other, sharing a basement and a roof. The floor between two stacked apartments is not part of the envelope, and insulating it does nothing for the heating bill. The envelope is the attic over the top unit, the outside walls of both, and the basement rim under the bottom one. The units may have separate thermostats and bills, but the air moves through them as one building, so we scope and price it as one.
After Sandy: insulating houses that took water or were raised
Hurricane Sandy put up to six feet of water into houses south of Montauk Highway, and on the northern side of the village people went more than a week without power. Both halves of that story matter for insulation. Where water came in, insulation below the waterline was ruined: fiberglass batts and cellulose hold water against the framing and have to come out. In a house that was gutted and rebuilt afterward, the lower walls may have new insulation while the attic still holds whatever was there before the storm, because the water never reached it.
Below a possible flood line, choose materials that tolerate getting wet and can dry. In a lower level or crawl space that could flood again, we keep paper-faced batts and loose cellulose out of the flood zone, insulate and seal the floor above a vented crawl space rather than the walls around it, and use closed cell foam at the rim joist and under the floor, where it air-seals and does not soak up water the way fibrous insulation does. If the house was raised onto a new foundation, the openings built into that foundation to let floodwater pass through are not air leaks. They stay open, and the insulated line goes in the floor above them, along with the plumbing and ducts that now run through that cold space.
The other half of the story is the week without power. A sealed and insulated house holds its temperature longer when the heat or the air conditioning stops, whether the cause is a storm or a failed boiler on a January night. In a village that has lived through it, that counts.
We seal before we insulate
Insulation slows heat conducting through a ceiling or wall. It does not stop air, and in an old house the air moves through the gaps nobody sees: at the sill, around the chimney, through the tops of the walls into the attic.
In a Lindenhurst cape the sequence starts in the basement: seal the sill where it meets the foundation, then seal and insulate the rim joist. Upstairs, block the floor bays under the knee walls at the eave line, put an air barrier on the back of each knee wall, and baffle the slopes. At the peak, seal the top plates, the plumbing vent, the light boxes and the chimney chase with metal and fire-rated sealant. Then insulate the knee walls, the slopes and the flat attic to depth. In a house near the water, the crawl space or raised floor is sealed and insulated before any of it.
If a quote specifies a depth of insulation and never mentions air sealing, it is half a job.
What insulation costs in Lindenhurst
Most of our projects run between $3,500 and $12,500. A 1950s ranch attic in Lindenhurst sits near the low end. A cape costs more, because the knee walls, slopes, flat attic and rim are four separate pieces of work. A pre-war house with empty walls adds blocking and dense-packing. A two-family is priced as one building. A raised house or a crawl space near the bay adds the floor above it. What spray foam costs is covered separately.
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 Lindenhurst
Lindenhurst’s electric company is PSEG Long Island, and most of the village is on National Grid gas lines. Because PSEG Long Island supplies the electricity, NYSERDA’s Comfort Home program is not available to Lindenhurst homes.
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 with a check of insulation and drafts, a thermal scan and a blower door test. Gas, oil, propane and electric heat all qualify, and the insulation must go in with blower-door-assisted air sealing. PSEG Long Island’s list is written for single-family homes, so the owner of a two-family should ask PSEG Long Island before counting on it.
National Grid’s Long Island insulation rebate program is not taking new applications, and income-eligible households now use EmPower+, which is open to one- to four-family homes and to renters. For a household under Suffolk County’s limit, NYSERDA’s EmPower+ program can pay for air sealing and insulation at no cost up to $14,000 for lower-income households (at or below $98,925 for a household of four), or half the cost up to $7,000 for moderate-income households (below $131,900 for four), through an EmPower+ contractor, plus up to $1,600 in federal HEAR funds for air sealing, insulation and ventilation. Long Island households should check eligibility on the MyEnergy portal.
These programs pay through their own participating contractors, so check before you sign. The federal insulation tax credit (Section 25C) ended for work placed in service after 31 December 2025, a 2026 job has no federal credit, and New York has no state tax credit for insulation. Our New York and New Jersey rebate guide covers every program in detail.
Code and climate in Lindenhurst
89.1% of Lindenhurst’s homes were built before 1980. New York’s first statewide energy code took effect on 1 January 1979, decades after most of the village’s capes, ranches and pre-war houses were standing. Suffolk County is Climate Zone 4.
New houses are now built to the 2025 Energy Conservation Construction Code of New York State, in force since 31 December 2025: R-49 ceilings, or R-38 over the whole ceiling where uncompressed R-38 extends at full height over the wall top plate at the eaves; R-30 floors; basement and crawl space walls at R-15 continuous, R-19, or R-13 plus R-5 continuous; U-0.27 windows; and air leakage no greater than 3.0 air changes per hour at 50 pascals.
An existing house is not held to that table. Unaltered parts do not have to comply, and New York’s code does not require a blower door test when you insulate an existing home. When an alteration exposes wall or roof cavities, though, they must be insulated to full depth. After a flood, when wet drywall comes off the lower walls, that rule means the cavities get filled completely before the walls close again. ENERGY STAR recommends R-60 for an uninsulated attic in this zone and R-49 where 3 to 4 inches are already in place.
Common questions about insulation in Lindenhurst
Do you install insulation in Lindenhurst, NY?
Yes, throughout the village: the 1,539 homes built before 1940, the 1940s and 50s capes and ranches that make up 42.5% of the stock, the 1960s and 70s high ranches, and the 1,029 homes in two-unit buildings, which we scope as one building. We also work on houses south of Montauk Highway that took water in Sandy or were raised afterward. We do not insulate the envelopes of larger apartment buildings. If you are not sure your house fits, ask on the phone.
How much does insulation cost in Lindenhurst?
Most projects run $3,500 to $12,500. A 1950s ranch attic is usually near the low end. A cape costs more because its knee walls, slopes, small flat attic and basement rim are separate pieces of work. Pre-war walls add blocking and dense-packing, and a two-family is priced as one building. A raised house or a crawl space near the bay adds the floor over it. The written scope and price come after a free walk-through, with no obligation.
Are there insulation rebates in Lindenhurst?
Yes. Lindenhurst is PSEG Long Island territory, and PSEG Long Island 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. Comfort Home is not available to PSEG Long Island homes. EmPower+ covers income-eligible one- to four-family homes, including two-families and renters. The federal 25C credit ended for work placed in service after 31 December 2025, and New York has no state credit.
Our house took water in Sandy. What insulation should go in the lower level now?
Anything that can flood again should tolerate water. Keep paper-faced batts and cellulose out of the flood zone, because they hold water against the framing and have to be torn out after the next event. Closed cell foam at the rim joist and under the floor air-seals and does not soak up water the same way. Over a vented crawl space, insulate the floor above rather than the walls around it. If the house was raised, leave the flood openings in the foundation open and insulate the floor above them.
Free energy audit in Lindenhurst
In a Lindenhurst house we start low: the basement or crawl space, water marks on the framing, the sill and rim, and in a raised house the floor and the flood openings below it. Then the upstairs of a cape, behind the knee walls and into the slopes, and the small attic at the peak. In a two-family we walk both units and the shared basement. If the attic is fine and the loss is at the sill and rim, we say so. Then a written scope and a price, with no charge and no obligation.
Call 914-825-6824 or use our contact form. Open 8am–8pm, seven days. We work out of New Rochelle, NY with a 100-plus in-house crew that never subcontracts.
Learn more
- Insulation contractors across Suffolk County
- Insulation in Copiague
- Insulation in North Lindenhurst
- Insulation in West Babylon
- Crawl space insulation
- Open cell and closed cell spray foam compared
- Insulation for older homes