Six Salisbury homes in ten heat with oil. 59.4% of occupied homes burn fuel oil, against 25.6% on utility gas, 7.3% on electricity and 2.8% on bottled gas, and another 3.2% report solar energy as their heating fuel. Salisbury, once called South Westbury, is an unincorporated hamlet in the Town of Hempstead, named for the broad, flat stretch of the Hempstead Plains that reminded 19th-century Long Islanders of the Salisbury Plain in England.
Its 4,418 housing units are almost all post-war. 62.7% were built in the 1950s and 17.7% in the 1940s, so 80.4% of the hamlet comes from those two decades, and only 2.6% has gone up since 2000. The median home dates from 1955. 85.0% of units are detached houses and 9.1% are attached, and 91.1% of occupied homes are owner-occupied.
So the usual Salisbury job is a compact 1940s or 50s house with an oil burner, owned by someone weighing a new boiler, a heat pump or panels on the roof. Sealing and insulating belongs at the front of that list.
The houses we insulate in Salisbury
Many Levitt-style homes stand beside Eisenhower Park, which was known as Salisbury Park, and they set the pattern for the hamlet: small capes and ranches of the late 1940s and 1950s, served by the Westbury station of the Long Island Rail Road. Houses in that mold were designed to grow, with a steep roof over an attic that a later owner could turn into bedrooms, and seventy-odd years on, the attic above a Salisbury house can be almost anything.
Where the attic was never finished, the work is the attic floor: sealing every hole in the ceiling below, blocking the eaves with baffles, and bringing the insulation to depth. Where it was finished, the upstairs has the familiar cape weaknesses, but the stair is the one owners overlook. The walls enclosing a stair to a finished attic often face straight into the unheated space behind the knee walls, framed with a batt and nothing on the attic side, and the stairwell carries warm air up past them all winter. A shed dormer across the back adds its cheek walls, a thin ceiling and a joint to the old roof that was rarely sealed.
A ranch loses heat through one low attic floor, and the first few feet in from the wall plate are the hardest to reach and the first to be left thin.
What sits under the house decides the lower half of the job. A basement puts the rim joist and sill on the list, sealed and insulated with closed cell foam. A crawl space puts its walls in question. A finished house on a slab has nothing to insulate from below, which moves the value overhead.
The 404 attached units, 9.1% of the stock, and the 116 units in buildings of ten to nineteen add a party wall or a shared roof to the conversation. A party wall left open where it enters the attic lets two homes share air, so it is closed first, and a roof held by an association is the association’s call.
The oil share changes how the savings show up. An oil-heated house pays for heat in advance, a tank at a time, so a sealed and insulated Salisbury house shows its savings as deliveries spaced further apart, and the dollar figure moves with the price of oil each winter. National Grid is the gas company, but with only 25.6% of homes on gas, whether a line reaches your street is a question for National Grid before a conversion is planned.
Solar panels over an oil burner: putting the Salisbury work in order
Panels on a roof make electricity. In a house heated by oil, they lower the electric bill and do not save a gallon of oil, and the attic under the array keeps losing heat exactly as it did before. With 3.2% of Salisbury homes already reporting solar as their heating fuel, what heats the house and what powers it are live questions here, and the order matters.
If a heat pump is part of the plan, seal and insulate first. The size of a heat pump follows the heat a house sheds on its coldest nights, and every kilowatt-hour it draws is electricity the panels would have to supply. Tighten the envelope before the heat pump is sized and the house needs a smaller unit that draws less power, so the same panels carry a larger share of the heating. Do it the other way round and the heat pump and the array are both sized for leaks that could have been closed.
The roof itself deserves a look before the panels go on. An array is bolted through the roof, and anything that has to happen on top of the deck later, such as a roof replacement or rigid insulation laid above the sheathing, means taking the panels off and putting them back. If the roof is near the end of its life, that is the time to replace it and to settle whether any insulation belongs above the deck. Work on the underside, from the attic, stays possible with panels in place.
Inside the attic, the installation brings its own openings. Conduit and wiring that pass through the roof deck or down through the attic to the electrical panel leave holes in the ceiling plane that should be sealed like any other, and junction boxes in the attic must stay reachable, so insulation goes around them rather than over them.
We seal before we insulate
Insulation resists heat moving through it; it does not stop air moving past it. A Salisbury house with a stairwell open to the knee-wall space and unsealed ceiling fixtures sends warm air up and out however deep the insulation is.
In a Salisbury cape with a finished attic the sequence is: seal the ceiling fixtures, the plumbing vent and the chimney gap, closing that gap with sheet metal and high-temperature sealant; close the floor bays under the knee walls at the eave line; put an air barrier on the attic side of the knee walls and the stairwell walls; seal the joint where a dormer meets the old roof; baffle the slopes. Then the rim joist and sill, if there is a basement. Then insulate, and after sealing, check that the oil burner’s chimney still drafts properly with the house’s exhaust fans running.
If a quote specifies a depth of insulation and never mentions air sealing, it is half a job.
What insulation costs in Salisbury
Most of our projects run between $3,500 and $12,500. An unfinished attic over a ranch or cape, sealed and insulated to depth, sits toward the lower end. A finished attic costs more for its knee walls, stairwell walls, slopes and any dormer. A basement rim adds a modest amount; a crawl space adds more. A party wall is its own line.
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 Salisbury
Salisbury’s electric company is PSEG Long Island, and its gas company is National Grid. Because PSEG Long Island supplies the electricity, NYSERDA’s Comfort Home program is not an option for a Salisbury home.
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. Oil heat does not rule a house out: its 2026 rules cover single-family homes heated with oil, natural gas, propane or electricity. Insulation must go in with blower-door-assisted air sealing.
National Grid’s Long Island insulation rebate program is not accepting new applications, and income-eligible households now use NYSERDA’s EmPower+. It can pay for air sealing and insulation at no cost up to $14,000 for lower-income households (in Nassau, 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. Long Island households should check eligibility on the MyEnergy portal.
PSEG Long Island’s REAP program offers a free in-home energy survey to customers at or below its 2026 income guidelines, $131,900 for a household of four, and may install items such as door sweeps, attic hatch covers and LED bulbs at no cost; it does not install insulation. Each program pays through its own participating contractors, so confirm with the program before you sign. 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. Our New York and New Jersey rebate guide has the details.
Code and climate in Salisbury
92.8% of Salisbury’s housing was built before 1980. Its Levitt-style capes and ranches were a generation old before New York’s first statewide energy code took effect on 1 January 1979. Nassau County is Climate Zone 4.
The 2025 Energy Conservation Construction Code of New York State, in effect since 31 December 2025, sets the bar for new homes: R-49 ceilings, met by R-38 over the whole ceiling where it keeps full, uncompressed 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; R-30 continuous for insulation laid entirely above a roof deck; and air leakage of 3.0 air changes per hour at 50 pascals or less.
For a house already built, the table is not the test. Its unaltered parts need not comply, and New York’s code does not require a blower door test when you insulate an existing home. Where a project exposes roof or wall cavities, they get insulated to full depth. ENERGY STAR recommends R-60 for an uninsulated attic in this zone and R-49 where 3 to 4 inches are already there.
Common questions about insulation in Salisbury
Do you install insulation in Salisbury, NY?
Yes, across the hamlet, including the Levitt-style homes near Eisenhower Park, in what was long called South Westbury. Most of our Salisbury work is the 1940s and 50s cape and ranch, 80.4% of the housing: unfinished attic floors, finished attics with knee walls, stairwells and dormers, eaves, basement rims and crawl spaces. We also seal around solar conduit, close party walls in attached homes, and check the oil burner’s draft once the house is tighter.
How much does insulation cost in Salisbury?
Most projects run $3,500 to $12,500. An unfinished attic sealed and insulated to depth is toward the lower end. A finished attic costs more because the knee walls, stairwell walls, slopes and any dormer each need sealing and insulation. A basement rim adds a little, a crawl space more, and a party wall in an attached home is priced on its own. The walk-through is free, and you get the scope and price in writing.
Are there insulation rebates in Salisbury?
Yes. PSEG Long Island, Salisbury’s electric company, lists a $2,500 insulation rebate and a $1,000 air-sealing rebate for market-rate single-family homes, with more for income-qualified homes, paid through its participating contractors after a free Whole House Energy Assessment, and oil-heated homes qualify. Comfort Home is not available to PSEG Long Island homes. Income-eligible households can check EmPower+ on the MyEnergy portal. The federal 25C credit ended for work placed in service after 31 December 2025, and New York has no state insulation credit.
We are about to put solar panels on our Salisbury roof. Should the attic be insulated first?
It helps to do it first, or at least to plan both together. Panels do not change how fast heat leaves through the attic, and if a heat pump may replace the oil burner, a sealed and insulated house needs a smaller one, so the same array covers more of it. Replace an aging roof before the panels go on, since work on top of the deck later means removing them. Attic work from inside can happen afterward, as long as the installer’s conduit holes are sealed and junction boxes stay reachable.
Free energy audit in Salisbury
We start at the top of a Salisbury house: whether the attic was finished, what is behind the knee walls and the stairwell walls, the dormer seam, the depth at the eaves, and any solar conduit or junction boxes. Then the ceiling fixtures and hatch, and down to the basement or crawl space, the rim and sill, the oil burner and its chimney. If the unfinished attic is fine and the stairwell is the leak, we say so. The written scope and price come at no charge and with no obligation.
Call 914-825-6824 or use our contact form. We are open 8am–8pm, seven days, and work out of New Rochelle, NY with a 100-plus in-house crew that never subcontracts.
Learn more
- Insulation contractors across Nassau County
- Insulation in Westbury
- Insulation in East Meadow
- Insulation in Levittown
- Attic insulation
- Roof insulation
- Spray foam insulation