The Home Insulators

Insulation Contractors in Randolph, NJ

The median Randolph house was built in 1978, the same year New Jersey’s first statewide energy subcode took effect, which makes the township a coin toss. 54.4% of its 9,315 units predate 1980. 36.1% went up in the 1980s and 90s, the largest single cohort here, with 19.4% in the 1990s alone. Half of Randolph was built with no insulation requirement at all, and half was built to an early and thin one.

74.8% of units are detached houses and 77.1% are owner-occupied, so nearly every job here is one owner deciding about one house. 6.0% of units are attached, 7.2% sit in two- to four-family buildings and 5.4% in buildings of twenty or more. Gas heats 69.9% of homes, oil 16.2% and electricity 11.4%. One house in six is still on a tank, and on oil the payback on air sealing lands faster than it does on the gas houses across the street.

Land here runs from 551 feet above sea level to 1,120 feet, all of it inside the New Jersey Highlands, and the State Planning Commission calls Randolph half rural, half suburban. High open lots are where a wind-washed eave turns into a January phone call.

The houses we insulate in Randolph

Start with the 1980s and 90s colonial, 36.1% of the township. Its walls are already full — batts in the stud bays under the codes of that period — so nobody should be selling you blown-in walls on one. What fails is everything the batt crew never touched. The attic has fiberglass laid between the joists with the top plates, the plumbing chase, the flue and the recessed cans open underneath it. The cathedral and tray ceilings were framed without baffles, so the slopes are wind-washed at the eave and the ceiling under them runs cold. The bonus room over the garage sits on joist bays open to the garage. In many, the air handler and ducts sit in the vented attic, outside the insulation, heating the roof deck.

The 1970s built 22.5% of Randolph on their own, and that decade is the split-level, the bi-level and the long ranch. A split gives you two attic planes at different heights, a bedroom over the garage, a cantilevered bay and a half-level of knee wall between the roof lines that almost never has an air barrier behind it. A bi-level puts its lower floor into the hillside, which on Highlands ground means a rim joist on block with paneling nailed over it. The ranch is one long low attic where the loose-fill has settled and thinned at the eaves.

The 1940s and 50s, 16.5% of the stock, are the small houses: capes, one-story cottages and the year-round conversions below. A cape fails at the knee wall — insulation on the room side, nothing behind it, joist bays running out to an open eave under the bedroom floor, slopes with no vent path above the batts. The 10.8% built in the 1960s is the early ranch, less in the attic.

Only 4.6% of the township predates 1940. The Combs Hollow Historic District carries buildings tied to industry from around 1735 to 1927, and iron mining goes back to 1713 here, which is what put the oldest neighborhoods — Ironia, Mount Fern, Center Grove, Mill Brook — where they are. In houses of that age we assume balloon framing until we open a bay, and knob-and-tube wiring comes out before anything goes into a wall.

The bungalow colonies that became year-round houses

Randolph spent the early twentieth century as a vacation haven known for its woods, ponds, lakes and air. Through the 1950s it was farms, large hotels and bungalow colonies; performers played the hotels and boxers trained at them. The hotels are gone. Plenty of the bungalows are still standing, sold off one at a time and lived in through the winter.

A summer bungalow was built to be empty in January. The floor sits over a crawl space or piers with no insulation and often no ground cover, so the first floor is cold before the heat is on. The walls may have no sheathing behind the siding, only building paper, so blown-in cellulose gets a check for gaps at the plate first. Ceilings were often finished right to the rafters with no attic at all, which makes the roof slope the insulated assembly with no vented cavity above it.

We scope those houses from the bottom up: insulate the floor over the crawl space or close the crawl at its walls, put a ground cover down, then work the slopes and whatever attic exists. Doing the roof first on a bungalow with an open floor is money spent on the wrong plane.

We seal before we insulate

Insulation slows heat moving through a surface. It does nothing about air moving through a gap. Blow a Randolph colonial attic to R-49 with the top plates open and the bath fan venting into it, and you have a deeper blanket over the same holes.

In a Randolph colonial the order is: seal the top plates, the chases, the recessed cans and the fan housings; weatherstrip the attic hatch; seal the garage ceiling under the bonus room and block its joist bays at the garage wall; baffle the cathedral and tray slopes so they can be filled without choking the eave; then insulate the attic flat, and seal and wrap the ducts if the air handler is up there. Then the rim joist. In a split that list runs twice, once at each attic level, plus the knee wall between them.

If a quote specifies a depth of insulation and never mentions air sealing, it is half a job.

What insulation costs in Randolph

Most of our projects run between $3,500 and $12,500. In a Randolph colonial the number moves with ceiling area, the feet of cathedral slope to baffle, the bonus-room floor and whether attic ductwork has to be sealed and wrapped. In a split it moves with the second attic level and the knee wall between the roof lines. In a converted bungalow it moves with the crawl space. What spray foam costs covers the foam side of the price.

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 Randolph

Randolph is JCP&L territory for electricity. Gas is New Jersey Natural Gas across most of the township, with PSE&G on a smaller slice, so the gas bill decides which gas program applies. The gas programs require gas heat, so a house in the 69.9% on gas starts with its gas utility and confirms with JCP&L. An oil or electric house starts with JCP&L.

JCP&L Whole Home Energy Solutions pays up to $7,500 in rebates: $2,000 once a modeled saving of five points is reached, then $200 for every percentage point above that, capped at $7,500 and at half the project cost. It adds 0% on-bill financing of $2,500 to $25,000, over 36, 60 or 84 months up to $10,000 and 120 months above that or for income-qualified customers. A participating contractor does the audit; JCP&L does not publish the fee. Its Whole Home Energy Assessment is a separate free walk-through for customers who own the home.

New Jersey Natural Gas Whole Home Energy Solutions, run under the SAVEGREEN name, uses the same formula to the same $7,500 cap and adds 0% on-bill repayment of up to $25,000. Every project must include insulation and air sealing, installed by June 30, 2027, and its Whole Home Energy Assessment is free for NJNG residential customers once every twelve months. A house on the PSE&G side of the gas map uses PSE&G Whole Home Energy Solutions instead: up to $7,500 plus 0% on-bill repayment of up to $25,000, through a BPI-certified contractor participating in PSE&G’s program.

At no cost: JCP&L Home Weatherization for Income-Qualified Customers installs up to $14,000 in upgrades and $2,500 in health and safety repairs for households between 250% and 400% of the federal poverty guidelines, in one- to four-unit homes at least five years old. The New Jersey Natural Gas Home Weatherization Program does the same for income-qualified customers who heat with its gas. New Jersey Comfort Partners covers households at or below 250% of the federal poverty guidelines, $82,500 a year for a family of four in 2026, and refers oil, propane and kerosene homes to the state’s Office of Weatherization — here, the 16.2% on oil and the 1.6% on bottled gas.

The New Jersey 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 mailer says. The full picture is in our New York and New Jersey rebate guide.

Code and climate in Randolph

54.4% of Randolph went up before 1980, most of it before New Jersey’s first statewide energy subcode of 1 January 1978. That is a lower share than most Morris towns carry, which is why the conversation here is usually about a house with some insulation rather than none. Morris County is climate zone 5A, along with Sussex, Warren, Passaic, Bergen, Somerset and Hunterdon.

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, and a complete permit application filed under the old code is still accepted until about 16 February 2027 — with walls at R-30 in the cavity or R-20 plus R-5 continuous, windows at U-0.28, and air leakage of 3.0 air changes per hour at 50 pascals. R-49 is the number the state considers right for this climate, and it is what we design to on a retrofit.

A house 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. Blown-in or batt insulation installed against the interior finish is ordinary maintenance with no permit; spray foam and other foam plastic insulation need a permit, which we pull as part of the job.

Common questions about insulation in Randolph

Do you install insulation in Randolph, NJ?

Yes. Most of our Randolph work is the 1980s and 90s colonial, 36.1% of the township: the attic flat, the cathedral and tray slopes, the bonus room over the garage and the ducts if they sit in the attic. We also do the 1970s splits and bi-levels, 22.5% of the stock on their own, the capes and small 1940s and 50s houses, and the former summer bungalows with cold floors over open crawl spaces.

How much does insulation cost in Randolph?

Most projects run $3,500 to $12,500. In a colonial the drivers are attic square footage, the feet of cathedral slope that need baffling, the floor over the garage and whether ductwork in the attic has to be sealed and wrapped. In a split it is the second attic level and the knee wall between the roof lines. In a converted bungalow it is the crawl space and the roof slopes. We give a written scope and a price after a free walk-through.

Are there insulation rebates in Randolph?

Yes. Electricity is JCP&L, and gas is New Jersey Natural Gas for most of the township with PSE&G on part of it. Each runs a Whole Home Energy Solutions program paying up to $7,500 in rebates for air sealing and insulation, with 0% financing of up to $25,000. Start with whichever utility bills your heating fuel. Comfort Partners does the work at no cost for households at or below 250% of the federal poverty guidelines. New Jersey’s IRA rebates have not launched, and the federal 25C credit is gone.

Our Randolph house still heats with oil. Is insulating it worth doing before we switch?

Yes, and it is worth doing first. 16.2% of the township heats with oil, and oil heat costs more per unit of heat delivered than gas, so the same air sealing and attic work returns more per year in an oil house than in the gas house next door. Sealing and insulating also shrinks the heating load, which means whatever you install later — a smaller boiler, a heat pump — can be sized smaller and costs less. Doing it in the other order buys equipment for a house that leaks.

Free energy audit in Randolph

We look at the top plates, chases, cans and fan ducts before we look at the depth of the insulation, then the slopes over cathedral and tray ceilings, the floor of any room over the garage, and the rim joist; on a split, both attic levels and the knee wall between them. In a converted bungalow we start in the crawl space. Then a written scope and a price, no charge.

Call 914-825-6824 or send the details through the contact form. Open 8am–8pm, seven days. We work out of New Rochelle, NY with a 100-plus in-house crew, and we hold manufacturer installer certifications from the spray foam manufacturers we use.

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