Wantagh was a farming area called Jerusalem long before it was a suburb, and the housing still shows both lives. 13.1% of its 5,970 housing units were built before 1940, 781 homes from before the suburb, and then the suburb arrived all at once: 40.5% of the stock dates from the 1950s and 19.8% from the 1960s. Only 3.0% has been built since 2000. Wantagh is an unincorporated hamlet in the Town of Hempstead, known as the Gateway to Jones Beach.
It is detached and owner-occupied: 94.6% of units are single-family detached houses, and 95.6% of occupied homes are lived in by their owners. The median home dates from 1957. 60.5% of homes heat with utility gas, and 32.6% burn fuel oil, with 3.0% on electricity and 1.6% on bottled gas.
So the typical Wantagh insulation job is a 1950s or 60s house on a lot of its own, with an owner who can decide, and in roughly one home in three an oil tank in the basement. The less typical one, an older farmhouse enlarged over a century, is where the harder decisions sit.
The houses we insulate in Wantagh
The area stayed mostly farmland until Sunrise Highway and Jones Beach were built in the early 20th century, and it did not take on a suburban character until the housing development of the 1950s through the 1970s. 50.8% of today’s stock is from the 1940s and 50s. On those streets the house is a cape or a ranch.
The Wantagh cape fails where its second floor meets the roof. The knee walls are framed partitions with insulation stapled to the room side and an open, unheated triangle behind them; the floor joists continue under those walls to the eave, so cold air runs beneath the bedrooms; the slopes hold whatever batt fit against the roof deck. Some have had a shed dormer added across the back, and the dormer’s side walls and ceiling rarely got more attention than the original. The ranch has one wide attic whose floor insulation has settled and been pushed away from the eaves by wind through the soffit vents, with every ceiling light, wall plate and plumbing vent open beneath it.
19.8% from the 1960s and 6.5% from the 1970s is a large second wave, and it brought the high-ranch and the split-level. In a high-ranch the upper floor sits over a garage and a half-buried lower level, so the garage ceiling is the floor of a bedroom or kitchen and the rim joist wraps the lower level at eye height. In a split, the floor over the garage and the wall where the upper level rises above the lower roof are the weak points; that wall often faces directly into an attic with no sheathing on its back.
The 6.7% from the 1980s and 90s include colonials with insulated walls and code-minimum attics. Their losses are at the attic hatch, the recessed lights, the bath fans and, where central air was part of the original build, ducts in the attic.
32.6% of homes burn fuel oil, and for them the payback of sealing and insulating shows up as fewer gallons delivered over a winter. National Grid gas is available on many Wantagh streets, not all, so some oil-heated owners can switch and some cannot without a bigger project. Either way, the house that needs less heat makes the next boiler, furnace or heat pump smaller and cheaper to run.
Before the suburb: Jerusalem’s farmhouses and the wings added to them
Early settlers called this place Jerusalem, and the creek that still runs north to south through it, covered over in many places but visible between the Wantagh Parkway and the developments west of Wantagh Avenue, was the Jerusalem River. The Jackson and Seaman families were among its oldest settlers. German Methodists moved out from New York City around 1850 to farm, and around the 1880s the place was renamed Ridgewood, and later Wantagh. The hamlet holds 9 of Nassau County’s 25 New York State Historical Markers, and the Samuel and Elbert Jackson House was listed on the National Register of Historic Places in 2006.
Most of the 781 pre-1940 homes are not landmarks, and a house that has stood that long has usually been enlarged in stages as a family or the next owner needed room: a kitchen wing, a sunroom, a second-story addition, a garage turned into a den. Each piece came from a different decade with a different idea of insulation, and the old part usually has none.
The trouble is at the joints. Where an addition’s roof meets the old house’s wall, there is often a hidden attic pocket with the old exterior wall, sometimes still clapboarded, standing open inside it, and the joist bays of the old floor running straight into that pocket. Air moves from the heated rooms into those spaces with nothing to stop it. Older sections may be balloon-framed, with stud bays open from cellar to attic, and may still carry knob-and-tube wiring, which we check before any cavity is filled. Foundations vary too: a cellar under the original house, a crawl space or slab under the wing.
On an old house whose outside matters, we work from inside: seal and insulate the attic and those hidden pockets, foam the rim in the cellar, close the crawl space under the wing, and fill walls from inside where they are open or being redone.
We seal before we insulate
Insulation slows heat moving through a surface; it does little about air moving through a gap. In a leaky house, the air does most of the damage, and the insulation on top of the leak only hides it.
In a Wantagh cape or ranch the order is: seal the top plates, wire holes, plumbing vents and ceiling boxes from the attic; close the chimney gap with metal flashing and fire-rated sealant; weatherstrip the hatch or pull-down stair; send the bath fan outdoors; block the joist bays under the knee walls; seal duct joints in the attic; then foam the rim and sill in the basement. In a high-ranch, the garage ceiling and the lower-level rim come first. Insulation follows, to depth, with baffles at the eaves.
If a quote specifies a depth of insulation and never mentions air sealing, it is half a job.
What insulation costs in Wantagh
Most of our projects run between $3,500 and $12,500. A 1950s ranch attic with sealing and a basement rim sits toward the lower end; a cape with knee walls, slopes and a rear dormer costs more. A high-ranch is priced on its garage ceiling and the rim around the lower level. An old farmhouse with additions is priced on the hidden attic pockets, the crawl space or slab under the wing, and any walls filled from inside, and it usually lands higher in the range.
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 Wantagh
Wantagh’s electric company is PSEG Long Island, and National Grid gas reaches many streets, not all. Because the electric company decides the lane on Long Island, NYSERDA’s Comfort Home program is not an option for a Wantagh home.
PSEG Long Island lists a $2,500 insulation rebate, a $1,000 air-sealing rebate and a $500 duct-sealing rebate for market-rate single-family homes, with higher amounts for income-qualified homes and homes in state-designated disadvantaged communities. They are paid through its participating contractors after a free Whole House Energy Assessment, which PSEG Long Island says includes a check of insulation and drafts, a thermal scan and a blower door test. Oil, gas, propane and electric heat all qualify under its 2026 rules, insulation must go in with blower-door-assisted air sealing, and ductwork in unconditioned space must be sealed.
National Grid’s Long Island insulation rebate program is not taking new applications. Income-eligible households go through NYSERDA’s EmPower+, which can pay for air sealing and insulation at no cost up to $14,000 for lower-income households, at or below $79,163 for a Nassau household of two, or half the cost up to $7,000 for moderate-income households, below $105,550 for two, through an EmPower+ contractor. National Grid gas customers who meet those income guidelines can also get no-cost home safety improvements through its Weatherization Health and Safety Program, after applying to EmPower+ and completing a no-cost Health and Safety Assessment. Long Island households should check eligibility on the MyEnergy portal.
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 rest.
Code and climate in Wantagh
90.2% of Wantagh’s housing was built before 1980. New York’s first statewide energy code took effect on 1 January 1979, so the hamlet’s farmhouses, capes, ranches and high-ranches were all built without one. Nassau County is Climate Zone 4.
New homes now fall under the 2025 Energy Conservation Construction Code of New York State, effective 31 December 2025. It requires R-49 in ceilings, satisfied by R-38 across the whole ceiling where that R-38 keeps its full, uncompressed height over the wall top plate at the eaves; R-30 in 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.
Existing houses are handled differently. The parts of a house you do not alter need not comply, and New York’s code does not require a blower door test when you insulate an existing home. Where an addition or renovation exposes wall or roof cavities, they get insulated to full depth at a minimum of R-3 per inch. ENERGY STAR recommends R-60 for an uninsulated attic in this zone and R-49 for one with 3 to 4 inches already in place.
Common questions about insulation in Wantagh
Do you install insulation in Wantagh, NY?
Yes, across the hamlet, north and south of Sunrise Highway and down toward Merrick Road. Most of our Wantagh work is in the 1950s capes and ranches and the 1960s high-ranches and split-levels: attics, knee walls, dormers, garage ceilings and basement rims. We also work on the older farmhouses with wings added over the years, where the hidden attic pockets and crawl spaces under additions are often the biggest losses, and on the newer colonials with attic ducts.
How much does insulation cost in Wantagh?
Most projects run $3,500 to $12,500. A ranch attic with air sealing and a basement rim is usually toward the lower end. A cape with knee walls, slopes and a rear dormer costs more, and a high-ranch is priced on its garage ceiling and rim. An enlarged farmhouse, with hidden attic pockets, a crawl space under the wing and walls filled from inside, usually lands higher. The walk-through and written price are free.
Are there insulation rebates in Wantagh?
Yes. PSEG Long Island, Wantagh’s electric company, lists a $2,500 insulation rebate, a $1,000 air-sealing rebate and a $500 duct-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. Oil heat qualifies. Income-eligible households can check EmPower+ on the MyEnergy portal. Comfort Home does not cover PSEG Long Island homes, the federal 25C credit ended for work after 2025, and New York has no state credit.
Our Wantagh farmhouse has an addition on the back, and the room where they join is always cold. Why?
Almost always because of a hidden pocket where the addition’s roof meets the old house. Behind that ceiling or knee wall, the old exterior wall often stands open in an unheated space, with the old floor’s joist bays running into it and no insulation or air barrier on either side. Cold air reaches the room from above and through the floor. We open an access, seal the joist bays and the old wall, insulate the pocket, and check the crawl space or slab under the addition.
Free energy audit in Wantagh
We start in the attic, and in an enlarged house in every attic space we can reach, including the pockets where roofs meet. Then the knee walls and dormer in a cape, the garage ceiling and lower-level rim in a high-ranch, the basement rim and sill, and the crawl space under any addition. In a pre-1940 house we check the wiring and whether the walls are open to the cellar. If the dormer matters more than the attic, we tell you. You get a written scope and a price, with no charge and 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 North Wantagh
- Insulation in Seaford
- Insulation in Bellmore
- Insulating older homes
- Crawl space insulation
- Air sealing