85.9% of Levittown’s 17,305 homes were built in the 1940s and 50s — 40.3% in the 1940s and 45.6% in the 1950s — and 93.5% are detached houses. The median home dates from 1952. Levitt & Sons started building here in 1947, a planned community for returning World War II veterans, and the hamlet, which sits in the Town of Hempstead, is still made of those houses and the ones that filled in around them: 6.5% from the 1960s, 2.1% from before 1940, and only 1.4% built since 2000.
Two more numbers set the job. 74.7% of occupied homes heat with fuel oil, against 20.1% on utility gas and 2.4% on electricity, and 93.7% are owner-occupied. The Levitt houses were built on concrete slabs with no basement, which moves nearly all of our Levittown work overhead.
The houses we insulate in Levittown
The first Levitt house was Bill and Alfred Levitt’s design for renters: a small one-floor house on a concrete slab with an unfinished “expansion attic,” the Levitt cape. The first 300 families moved in on 1 October 1947, when the place was still called Island Trees. Once the expansion attic becomes bedrooms it has a cape’s failures: short knee walls with nothing behind them, floor bays running out under the knee wall to the eave, rafter slopes with no baffle, and a shallow flat above the collar ties. A dormer adds two cheek walls to the same air path. Where the attic was never finished, the job is an attic floor, the eaves, and every hole cut through the ceiling below.
In 1949 the firm switched to a “ranch” sold outright: 32 by 25 feet, on a slab, with an expandable attic, no garage and hot-water radiant heating pipes. A carport and a built-in television arrived in 1950, and in 1951 a partially finished attic. That last change matters: a room built into part of the attic leaves the rest as unconditioned space, and the short walls and sloped ceilings between the two are where it loses heat. So does the carport. Where one has been closed in as a garage or a room, the new walls stand on a slab edge that was probably never insulated, under a roof that may not connect to the main attic.
The hamlet’s boundary also takes in streets built by other developers. If yours is one of the 6.5% from the 1960s, a raised ranch or split, the failures are that era’s: a bedroom over the garage with open joist bays under it, a cantilevered overhang, and a long low attic of settled loose-fill.
74.7% oil heat changes how the savings arrive. An oil-heated house pays for every gallon it loses, so a sealed and insulated Levittown house shows its savings as fewer tank fills, and the payback moves with the price of oil from one winter to the next. We size the job on what the house loses, not on this year’s delivery price. If a heat pump is in your plans, tighten the envelope first: a heat pump is sized to the heat a house loses.
Thirty houses a day: what a production house means for the attic
Bill Levitt came home from the Navy’s Seabees knowing how to put up military housing from uniform, interchangeable parts, and he bought options on onion and potato fields in undeveloped sections of Long Island to use it on. Pre-cut lumber and nails came from its own factories in Blue Lake, California. Every house was broken into 26 steps, and by July 1948 the crews were producing 30 houses a day. Building on concrete slabs took a negotiated change to the building code, which until then did not allow them. By 1951, Levittown and the surrounding area held 17,447 Levitt & Sons homes, and the development is widely regarded as the archetype for postwar suburbs across the country.
For insulation that history cuts two ways. The houses were near-identical when new, so we know the weak points before we climb the ladder: the eave, where a low roof meets the wall plate with little room for insulation; the flue chase; the ceiling boxes; the attic access; the slab edge. But nearly eighty years of owners have done different things to the same house — a finished attic, a dormer, a rear addition, a closed-in carport — so we scope every attic on its own, not from a floor plan.
The Levittown in the figures above does not match the 11756 ZIP code or the extent of the Levitt development. Levitt houses also stand under Wantagh and Westbury addresses in the Town of Hempstead and Hicksville addresses in the Town of Oyster Bay, and everything here about slabs and expansion attics applies to them.
We seal before we insulate
Insulation slows heat moving through a surface. It does nothing about air moving through a gap, and in winter the warm air in a one-story house leaves through its ceiling.
In a Levitt house the sequence starts overhead. Seal the flue or chimney chase, the plumbing vent, the top plates of the interior walls, the ceiling boxes and the attic hatch or stair. In a finished expansion attic, 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. Where trim comes off at the floor, seal the bottom plate to the slab. Then insulate, to depth.
If a quote specifies a depth of insulation and never mentions air sealing, it is half a job.
What insulation costs in Levittown
Most of our projects run between $3,500 and $12,500. In a Levitt slab house, with no basement or crawl space, the job is priced almost entirely overhead. An unfinished expansion attic with an open floor sits at the lower end: seal the plane, baffle the eaves, fill the floor. A finished attic with a dormer costs more, because every knee wall, slope and cheek wall is its own piece of work. A closed-in carport or a rear addition adds a separate roof. For the foam side of the number, see what spray foam 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 Levittown
Levittown’s electric company is PSEG Long Island. Its gas company is National Grid, but gas lines reach only parts of Levittown; many homes heat with oil, propane or electricity. Because the electric company is PSEG Long Island, NYSERDA’s Comfort Home program is not open to these homes. The lane is PSEG Long Island’s own.
PSEG Long Island lists a $2,500 insulation rebate and a $1,000 air-sealing rebate for market-rate single-family homes, plus $500 for duct sealing, with higher amounts for income-qualified homes and homes in state-designated disadvantaged communities. The rebates are paid through its participating contractors after a free Whole House Energy Assessment, which includes a check of insulation and drafts, a thermal scan and a blower door test. The rules fit a Levitt house: single-family homes heated with oil, natural gas, propane or electricity are all eligible, so oil heat does not shut you out, but the insulation must go in with comprehensive, blower-door-assisted air sealing.
National Grid’s Long Island insulation rebate program is not taking new applications; income-eligible households go through EmPower+. If your household income is under Nassau’s EmPower+ 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 family of four), or half the cost up to $7,000 for moderate-income households (below $131,900 for four) — through an EmPower+ contractor, with up to $1,600 more for air sealing, insulation and ventilation from federal HEAR funds. Renters can apply. Long Island households should check eligibility on the MyEnergy portal.
Each of these programs pays through its own participating contractors, so check the contractor 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. The details are in our New York and New Jersey rebate guide.
Code and climate in Levittown
95.9% of Levittown’s housing was built before 1980. The Levitt houses of 1947 to 1951 went up roughly three decades before New York’s first statewide energy code took effect on 1 January 1979. Nassau County is Climate Zone 4.
The code in force is the 2025 Energy Conservation Construction Code of New York State, effective 31 December 2025. For a new home it calls for R-49 in the ceiling — or R-38 over the whole ceiling where the full height of uncompressed R-38 extends 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, windows at U-0.27, and air leakage no higher than 3.0 air changes per hour at 50 pascals. A new heated slab gets R-10 continuous for 4 feet at the edge plus R-10 under the full slab; no slab poured in 1948 can be brought to that from above.
For a house already standing, unaltered parts do not have to comply, so insulating the attic does not drag the slab to the new-home table. New York’s code does not require a blower door test when you insulate an existing home, though PSEG Long Island’s rebates call for blower-door-assisted air sealing. Where an alteration opens roof or wall cavities, the exposed cavities must be filled to full depth. The R-38 eave condition is the one to watch in a Levitt ranch: getting full-height insulation over a low wall plate takes baffles, and sometimes closed cell foam at the eave. ENERGY STAR recommends R-60 for an uninsulated attic in this zone, or R-49 where 3 to 4 inches are already down.
Common questions about insulation in Levittown
Do you install insulation in Levittown, NY?
Yes. Most of our Levittown work is the Levitt house itself, part of the 85.9% of the hamlet built in the 1940s and 50s: the original capes with an expansion attic, finished or not, and the 1949–51 ranches with low eaves, carports and partially finished attics, all on concrete slabs. We also work on the 1960s raised ranches and splits, rear additions and closed-in carports, and the Levitt houses that carry Wantagh, Westbury or Hicksville addresses.
How much does insulation cost in Levittown?
Most projects run $3,500 to $12,500. In a Levitt slab house nearly all of the cost is overhead, because there is no basement rim or crawl space to do. An unfinished expansion attic with an open floor sits at the lower end. A finished attic with knee walls, slopes and a dormer costs more, and a closed-in carport or rear addition adds its own roof. We give a written scope and price after a free walk-through.
Are there insulation rebates in Levittown?
Yes, through PSEG Long Island, Levittown’s electric company. It 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 are eligible. Comfort Home is not open to PSEG Long Island homes. Income-eligible households can use EmPower+. The federal 25C credit ended for work placed in service after 31 December 2025, and New York has no state insulation tax credit.
Our Levittown house sits on a slab. Can the floor be insulated?
Not from underneath. An existing slab rests directly on the ground, and nobody can reach below it without breaking it out. If the heat still runs through radiant pipes in the slab, the perimeter is where much of it escapes, and that edge is hard to reach on a finished house. What we can do is stop the air: seal the bottom plates where walls meet the slab when trim is off, and seal and insulate the attic, where a one-story house loses much of its heat. A cold floor in a closed-in carport is a separate question we look at on site.
Free energy audit in Levittown
In a Levitt house we start in the attic: whether the expansion attic was finished, how far the knee walls run, what is in the slopes and the flat, how the eaves are vented, and every chase through the ceiling. Then the ground floor: the utility room, any closed-in carport or rear addition, and the ceiling over each. If the attic floor is fine and the loss is a dormer and a converted carport, we say so. Then a written scope and a price. No charge, 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 Nassau County
- Insulation in Wantagh
- Insulation in Hicksville
- Insulation in Westbury
- Attic insulation
- Spray foam for knee walls, slopes and low eaves
- Air sealing