73.8% of North Valley Stream’s 5,482 housing units were built in the 1940s and 50s: 1,466 homes in the 1940s and 2,582 in the 1950s. Only 6.2% predates 1940, and the median home dates from 1954. North Valley Stream is an unincorporated hamlet in the Town of Hempstead, named for its place north of the Incorporated Village of Valley Stream, and it is a separate place from that village, with a housing stock of its own.
Owners live in 93.9% of occupied homes. 83.6% of units are single-family detached houses, 5.0% are attached, 3.1% are in two-unit buildings and 5.6% in buildings of three or four. Heat is 64.7% utility gas and 29.1% fuel oil, with 3.5% on electricity and 1.1% on bottled gas. The Southern State Parkway runs west to east through the middle of the hamlet, roughly cutting it in half, and Valley Stream State Park lies mostly inside it.
So a North Valley Stream job is almost always a post-war house, a cape or a ranch, with an owner living in it and, in 29.1% of homes, an oil tank in the basement.
The houses we insulate in North Valley Stream
The 1,466 houses of the 1940s, 26.7% of the stock, are the oldest large group. The cape of those years was usually built small, with a half-story in the roof that was sometimes left unfinished and turned into bedrooms later. Where that happened, the upstairs has the cape’s classic failures — short knee walls with nothing behind them but open attic, floor joists running under those walls out to the eave, rafter slopes with a thin batt and no vent channel, a flat attic above the collar ties too shallow to walk in — plus whatever the owner who finished it used for insulation.
The 2,582 houses of the 1950s add ranches to the capes. A ranch attic is one long, low space, and its losses are simple and widespread: loose-fill that has settled and been blown back from the eaves, a hatch with no weatherstripping, a bath fan venting into the attic, ceiling boxes, the plumbing vent and the flue chase open beneath the insulation. Where a basement sits under either house, the rim joist and sill run bare around the whole perimeter, and that is where winter air comes in low.
Asbestos-cement shingle siding was common on houses of both decades, and where it is still on a house it settles how the walls can be filled. We do not drill through it. Walls get filled from inside, or by lifting shingles with care, and in a small cape the walls are rarely the first priority anyway.
After 1960 building slowed: 5.4% of the stock is from the 1960s, 3.8% from the 1970s and 2.8% from the 1980s. Then it picked up again, and 7.5% has gone up since 2000, including 227 homes from the 2010s. Those newer houses have full walls; their losses are ducts in the attic, recessed lights and the room over the garage. The 309 units in three- and four-unit buildings and the 171 in two-unit buildings are scoped as whole buildings, because the stairs, floors and attics are shared.
In homes on gas, sealing and insulating shows up on the National Grid bill. In the homes on oil it shows up as fewer deliveries, and the payback moves with the price of oil from one winter to the next, so we plan the work on where the house loses heat, not on this year’s delivery price.
North Valley Stream is not the Village of Valley Stream
The two names cause confusion, so it is worth being exact. The Incorporated Village of Valley Stream, to the south, is a village with its own government and a page of its own. North Valley Stream is a hamlet, with no village government; the Town of Hempstead is its local government. Valley Stream State Park straddles the two: most of it is in the hamlet, with a small portion extending south into the village.
For insulation, much is the same on both sides. Both are PSEG Long Island electric territory, so the same rebate lane applies, and both sit in Nassau County’s Climate Zone 4 under the same state energy code. What differs is the house. North Valley Stream’s stock is overwhelmingly from the 1940s and 50s, with little from before the war and few two-family buildings, and no rail line passes through the hamlet; the nearest Long Island Rail Road stations, Valley Stream on the Atlantic Branch and Westwood and Malverne on the West Hempstead Branch, are outside it. A typical job here is a post-war cape or ranch, not a railroad-era house.
The hamlet was also reshaped by a road. In the 1950s the Southern State Parkway was widened from four lanes to six through North Valley Stream, and roughly 213 homes in its path had to be moved or demolished. Central Avenue, Corona Avenue, Dutch Broadway, Fletcher Avenue and Linden Boulevard are its other main roads, and with 73.8% of the stock from the 1940s and 50s, a cape north of the parkway is usually the same job as a cape south of it.
We seal before we insulate
Insulation slows heat moving through a surface. It does nothing about air moving through a gap, and in a small post-war house a few large gaps can undo a full attic of insulation.
In a North Valley Stream cape the order is: block the joist bays under the knee walls at the eave line; put an air barrier on the back of each knee wall; seal the top plates, the plumbing stack and the ceiling boxes; close the chimney chase with sheet metal and high-temperature sealant; duct the bath fan outdoors; baffle the slopes; then insulate the knee walls, slopes and flat to depth. In a ranch the attic floor gets sealed first and the eaves baffled before any loose-fill goes down. Then the basement rim and sill.
If a quote specifies a depth of insulation and never mentions air sealing, it is half a job.
What insulation costs in North Valley Stream
Most of our projects run between $3,500 and $12,500. A 1950s ranch attic with air sealing, eave baffles and a basement rim sits toward the lower part of the range. A 1940s cape with a finished upstairs costs more, because each knee wall, slope and floor bay at the eave is its own piece of work. Walls behind asbestos-cement siding are filled from inside, which adds patching. A three- or four-unit building is priced as one building.
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 North Valley Stream
North Valley Stream’s electric company is PSEG Long Island, and most of the hamlet is on National Grid gas lines; National Grid can confirm a given street. Because the electric company is PSEG Long Island, NYSERDA’s Comfort Home program is not open to these homes.
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. 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-heated homes are eligible, and the insulation must go in with blower-door-assisted air sealing. The list describes single-family homes, so owners of the two- to four-unit buildings should ask PSEG Long Island what applies.
National Grid’s Long Island insulation rebate program is not taking new applications; income-eligible households go through EmPower+, which covers owners and renters of one- to four-family homes. NYSERDA’s EmPower+ 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 Nassau family 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.
NYSERDA’s Green Jobs–Green New York program offers loans of $1,500 to $25,000 over 5, 10 or 15 years, which must be repaid. Each program pays through its own participating contractors, so check the program’s contractor list 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 covers the rest.
Code and climate in North Valley Stream
89.2% of North Valley Stream’s housing was built before 1980. New York’s first statewide energy code took effect on 1 January 1979, a generation after the hamlet’s capes and ranches went up. Nassau County is Climate Zone 4.
The 2025 Energy Conservation Construction Code of New York State has applied since 31 December 2025. For a new home it requires R-49 ceilings, or R-38 across the whole ceiling where full-height, 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; U-0.27 windows; and air leakage no higher than 3.0 air changes per hour at 50 pascals.
For a house already standing, unaltered portions do not have to comply, and New York’s code does not require a blower door test when you insulate an existing home. Where an alteration exposes wall or roof cavities, they must be 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 down, a depth a shallow cape flat can reach only with care at the eaves.
Common questions about insulation in North Valley Stream
Do you install insulation in North Valley Stream, NY?
Yes, on both sides of the Southern State Parkway. Most of our work in the hamlet is the 1940s and 50s house, 73.8% of the stock: cape knee walls, slopes and shallow flats, ranch attics with settled loose-fill, and basement rims. We also work on the newer houses built since 2000, where ducts and garage rooms are the job, and on two- to four-unit buildings, which we scope as one building. The Village of Valley Stream, to the south, is a separate place, and we work there too.
How much does insulation cost in North Valley Stream?
Most projects run $3,500 to $12,500. A ranch attic with sealing, baffles and a basement rim is usually toward the lower part of the range. A 1940s cape whose upstairs was finished costs more, because the knee walls, slopes and eave bays are separate pieces of work. Walls behind asbestos-cement siding are filled from inside and patched. A three- or four-unit building is priced as one building. The walk-through and the written price are free.
Are there insulation rebates in North Valley Stream?
Yes, through PSEG Long Island, the hamlet’s electric company. It lists a $2,500 insulation rebate, a $1,000 air-sealing rebate and $500 for duct sealing 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-heated homes qualify. Income-eligible owners and renters can check EmPower+ on the MyEnergy portal. Comfort Home is not available to PSEG Long Island homes, the federal 25C credit ended for work placed in service after 31 December 2025, and New York has no state insulation credit.
Our North Valley Stream house still has its original asbestos-cement shingle siding. Can the walls be insulated?
Yes, without disturbing the siding. Asbestos-cement shingles should not be drilled, cut or broken, so we fill the stud bays from inside through small holes in the plaster or drywall, dense-pack them and patch, or work through open framing if a room is being redone. If you plan to replace the siding, its removal is a job for a licensed abatement contractor, and that is also the best moment to fill the walls from outside. In a small cape, check the knee walls and attic first; they usually lose more.
Free energy audit in North Valley Stream
We start in the attic: the flat, the knee-wall spaces behind the upstairs rooms, the slopes and eaves, the hatch, and every chase and fixture through the ceiling. Then the basement rim and sill, the pipe and fuel-line penetrations, the siding type and what is in the walls, and the floor over any garage. If the attic is fine and the draft is coming in at the 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 Nassau County
- Insulation in the Village of Valley Stream
- Insulation in Elmont
- Insulation in Franklin Square
- Attic insulation
- Wall insulation
- Air sealing