47.1% of Elizabeth’s 48,940 housing units are in two- to four-family buildings: 15,665 units in two-unit buildings and 7,398 more in buildings of three or four. Only 13.3% of the city is a detached house and another 5.5% is attached. The two-family is the Elizabeth house, and it is good work — an attic or roof cavity, a stair chase, a cellar, a rim joist, and one owner who can approve all of it at once.
The number that decides more jobs here than any other is 25.4%, the owner-occupied share, the lowest of the Union County towns we cover. New Jersey’s rebate program pays only on a one- to four-unit home the owner lives in. An owner living downstairs in a Peterstown two-family is squarely inside it. A tenant upstairs is not, and neither is a landlord who lives elsewhere, though that landlord can still hire us and pay for the work himself.
The 19.3% of units in buildings of twenty or more is not our market, and neither are most buildings of five to nineteen units: those envelopes belong to boards and managing agents working through capital plans. What follows is about the houses.
The houses we insulate in Elizabeth
The median Elizabeth unit dates from 1955, but the city was built in two long waves that sit in different neighborhoods. 27.5% of the stock — 13,482 units — predates 1940. 28.6% went up in the 1940s and 50s, 19.0% in the 1960s and 70s, 10.4% in the 1980s and 90s and 14.4% since 2000. Gas heats 86.0% of occupied units and oil only 2.0%, so this is a gas-bill town.
Elizabethport is the oldest ground in the city, the blocks east of 7th Street that grew around the port and the Singer works, and Peterstown and Keighry Head were both laid out at the end of the 19th century. The pre-1940 house on those streets is a tall, narrow, two- or three-story frame two-family on a deep lot. It is balloon-framed until proven otherwise, so the wall cavities run uninterrupted from the cellar sill to the attic and carry cellar air straight up behind the plaster. We block them at the top and bottom plates before anything is dense-packed, and we assume knob-and-tube wiring at that age — it comes out before insulation goes into a wall. The stair chase between the units is usually the biggest single hole in the building.
Many of those houses carry a flat or low-slope roof over the top unit instead of a vented attic. With no attic floor to blow, the insulation plane is the roof deck: closed cell foam against the underside, or rigid board above it at the next reroof. Where a third floor is finished under a pitched roof, common in the taller Elizabethport and Frog Hollow houses, the failure is the knee wall — batts on the room side, nothing on the back, open joist bays running out to the eave.
The 1940s and 50s built the capes and small colonials of Elmora, Elmora Hills and Westminster, on the wider streets at the western and northern edges. Elmora Hills was once Shearerville, annexed back from Union Township early in the 20th century; Westminster is the Tudor estate ground along the Elizabeth River near Liberty Hall. A cape there fails at the knee wall and the unbaffled slopes; a 1950s ranch fails across a shallow attic of settled loose-fill and unsealed top plates. The 1960s and 70s added brick two-families, often with a tuck-under parking bay and open joist bays under the bedroom above.
The North End went up mostly in the 1920s for workers at the Duesenberg plant; Bayway, against the Linden line, was built at the turn of the 20th century for refinery workers. The newest 14.4% is the waterfront townhouses and duplexes at Elizabethport and the new two-family houses around The Point. Those walls were built full under the 2000s codes, so blown-in walls are the wrong sale there. What fails is the party wall left open into both attics, the garage ceiling, the air handler in a vented attic, and bath fans dumping into the roof cavity.
Who owns the building decides what happens
Three quarters of occupied units in this city are rented, and that changes the first question we ask. If you own the home and live in it, you are the whole decision and the utility programs are open to you. If you own a two- to four-family and rent both sides, the work still pays — a shared stair chase costs the same money whoever sleeps upstairs — but the Whole Home rebate is written for owner-occupied homes, so price the job without it. If you rent, we cannot sell you the job; book the utility’s free walk-through and hand the report to the owner.
A two-family is always scoped as one building. The stair chase, the floor cavity between units and the cellar run through both apartments, and sealing one side of a shared air path does nothing.
We seal before we insulate
Insulation slows heat moving through a surface. It does nothing about air moving through a gap. Fill a balloon-framed wall with cellulose while the cavity is still open to the cellar and you have paid for cellulose sitting in a chimney.
In an Elizabeth two-family the order is fixed. Block the wall cavities at the sill and the top plate. Close the stair chase at the attic plane and the floor cavity between the units. Seal the plumbing stack and the chimney chase. Seal the cellar ceiling and the rim, because with one heating plant downstairs the cellar is the air source for the whole building. Then insulate: the flat attic or the roof deck, the knee walls and slopes, and the wall cavities last.
If a quote specifies a depth of insulation and never mentions air sealing, it is half a job.
What insulation costs in Elizabeth
Most of our projects run between $3,500 and $12,500. A two-family is priced as one building, and what moves the number is the roof area over the top unit, whether that roof is a vented attic or a flat deck that has to be foamed, the count of wall bays to block and dense-pack, and how much of the cellar ceiling and rim is reachable. A three- or four-family adds a stair chase; a waterfront townhouse is a smaller scope of party wall, garage ceiling and ducts. For the foam side, see what spray foam insulation 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. After air sealing and insulating, homeowners typically save 20% or more on heating and cooling.
Insulation rebates in Elizabeth
Elizabeth is PSE&G for electric and Elizabethtown Gas for gas. With 86.0% of the city on gas heat, most owners should start with Elizabethtown Gas, the utility that bills them for heat, and confirm with PSE&G. Either utility’s Whole Home program can take the lead; the contractor’s program approvals usually settle which one does.
Elizabethtown Gas Whole Home Energy Solutions pays up to $7,500 in rebates — $2,000 for a modeled 5% energy saving plus $200 for every point above that, and not more than half the project cost — plus 0% on-bill repayment of $2,500 to $25,000 over 7 years, or 10 above $10,000. It needs an active Elizabethtown Gas account and gas heat, and covers single-family, townhome, condo and multifamily buildings under four units. PSE&G Whole Home Energy Solutions is the electric-side route: up to $7,500 in rebates plus 0% on-bill repayment of up to $25,000, through a BPI-certified contractor in PSE&G’s program. PSE&G does not publish per-measure amounts.
The Whole Home assessment itself is priced by the contractor. The free item is the separate Whole Home Energy Assessment walk-through, offered by both utilities, which installs small no-cost items and points you at the program.
Two no-cost programs sit underneath. Elizabethtown Gas Home Weatherization for Income-Qualified Customers gives up to $14,000 in upgrades and $2,500 in health and safety repairs at no cost for households between 250% and 400% of the federal poverty guidelines, in 2026 $82,501 to $132,000 for a family of four; PSE&G Home Weatherization does the same in the same band. Below that, New Jersey Comfort Partners works at no cost at or below 250% of the guidelines, $82,500 for a family of four, in buildings of 1 to 14 individually metered units — most of this city’s stock. Oil and propane homes go to the state weatherization office instead.
New Jersey’s IRA Home Energy Rebates have not launched — the state says they are in development and not open for applications. The federal Section 25C tax credit ended for anything placed in service after 31 December 2025, so there is no federal insulation credit on a 2026 job, whatever a contractor may still be advertising. The full picture is in our New York and New Jersey rebate guide.
Code and climate in Elizabeth
75.2% of Elizabeth went up before New Jersey’s first statewide energy subcode of 1 January 1978, and the 27.5% that predates 1940 was framed before anyone wrote an insulation requirement at all. Union County is climate zone 4A.
New Jersey adopted the 2024 IECC on 17 August 2026. For new construction it sets R-49 ceilings — the 2021 edition it replaced called for R-60 — walls at R-30 in the cavity or R-20 plus R-5 continuous, windows at U-0.30 in the 4A counties, and air leakage of 3.0 air changes per hour at 50 pascals. A permit application filed complete under the old code is accepted until about 16 February 2027. R-49 is what we design to.
A building already standing falls under New Jersey’s Rehabilitation Subcode. Insulating an attic does not require bringing the rest of the house to code and does not require a blower-door test, which matters in a 1900s two-family where nobody wants to open a wall they did not plan to open. Blown-in or batt insulation against the interior finish is ordinary maintenance with no permit; spray foam needs a permit, which we pull as part of the job.
Common questions about insulation in Elizabeth
Do you install insulation in Elizabeth, NJ?
Yes. Most of what we do here is the two- to four-family house, 47.1% of the city, in Elizabethport, Peterstown, Keighry Head, Frog Hollow, Bayway and the North End, plus the detached capes and colonials of Elmora, Elmora Hills and Westminster and the newer waterfront townhouses. We do not work on the towers and larger apartment buildings, where the envelope belongs to a board or a managing agent. Call and we will tell you which side of the line your building sits on.
How much does insulation cost in Elizabeth?
Most projects run $3,500 to $12,500. A two-family is quoted as one building, and the drivers are the roof over the top unit, whether it is a vented attic or a flat deck that needs foam, the number of wall bays to block and dense-pack, and cellar access. A three- or four-family adds another stair chase and more floor area between units. A newer duplex half or townhouse is a smaller scope. You get a written scope and price after a free walk-through.
Are there insulation rebates in Elizabeth?
Yes, if you own the home and live in it. Elizabeth is Elizabethtown Gas for gas and PSE&G for electric, and either Whole Home Energy Solutions program pays up to $7,500 in rebates with 0% repayment behind it. Both utilities also offer a free Whole Home Energy Assessment walk-through. Income-qualified households can get the work at no cost through Comfort Partners or the utilities’ weatherization programs. New Jersey’s IRA rebates have not launched, and there is no federal 25C credit on a 2026 job.
We rent the top floor of a two-family in Elizabeth. Can we get the attic insulated?
Not on your signature. The attic, the roof and the walls belong to the owner, and so does the decision. What a tenant can do is book the utility’s free Whole Home Energy Assessment, which installs small items and produces a written report, then hand that report to the landlord. If the owner wants to move on it, we will walk the building with them. If the owner lives downstairs, the building qualifies for the rebate program and the case is easy to make.
Free energy audit in Elizabeth
We walk the attic or the roof cavity over the top unit, the stair chase, the knee walls if the third floor is finished, the cellar ceiling and the rim, and we check a wall cavity at the sill to see whether the framing is balloon or platform. Then a written scope and a price. No charge, no obligation. If the attic is fine and the real money is the cellar ceiling and the stair chase, that is what we will tell you.
Call 914-825-6824 or use the contact form. Open 8am–8pm, seven days. We work out of New Rochelle, NY with a 100-plus in-house crew, we never subcontract, and we hold manufacturer installer certifications from the spray foam manufacturers we use.
Learn more
- Insulation contractors across Union County
- Insulation contractors in Linden
- Insulation contractors in Union Township
- New York and New Jersey insulation rebates in full
- Insulating an older home
- Air sealing
- Closed cell spray foam