Walls are the surface most Camden County homeowners assume they cannot do anything about, and usually they are wrong. 71.7% of the county’s 213,188 units went up before New Jersey’s first statewide energy subcode of 1 January 1978, and in the older towns the stud bays behind the plaster are empty or hold a thin batt that has slumped down the cavity. Wall insulation in an existing house comes down to one question: is the wall open or closed? An open wall, in an addition or a gut renovation, takes batts, mineral wool or foam between the studs. A closed wall has three routes — filled through drilled holes, boarded from outside when the siding comes off, or opened.
Finding out what is in there comes first, and it is a five-minute job. Kill the power to an outlet on an exterior wall, take the cover plate off and look into the gap beside the box with a flashlight; do it on each floor and in the older and newer parts of the house, because one insulated wall does not mean all of them are. An infrared scan on a winter visit shows the rest: empty bays, blocking and voids read clearly when it is cold out.
Where wall insulation pays in Camden County houses
Pre-war frame houses, once the framing is understood. Haddonfield is 51.0% pre-1940, Collingswood 46.5%, Haddon Township 26.9% and Pennsauken 18.9%. Many of those houses are balloon-framed, with stud bays running unbroken from the cellar sill to the attic, and those walls need blocking at top and bottom before they can be dense-packed at all. Two other findings stop the work: knob-and-tube wiring, which an electrician replaces before insulation goes near it, and lath and plaster worth keeping, since drilling from outside can break the plaster keys and drilling inside raises dust in a house that predates 1978. Haddonfield established a historic preservation district in 1971, the second in the state, so there the outside route is agreed before it is priced.
Post-war capes and ranchers with hollow 2×4 walls. Pennsauken is 37.2% 1940s and 50s, Haddon Township 36.3% and Cherry Hill 22.4%. These are simple drill-and-fill candidates: regular bays, vinyl or aluminum siding on many of them, and a real comfort difference in the rooms on the windward side. Original cement shingles get tested before anyone drills them. A cape also has the wall that gets forgotten — the knee wall upstairs, which the code treats as a framed wall and which needs an air barrier on the attic side, not just a batt facing the bedroom.
Splits and two-story tracts of the 1960s and 70s. Cherry Hill is 48.4% that era and Gloucester Township 38.1%. The wall shared with an attached garage is the one worth spending on here, along with the gable ends that need staging and the band of wall above a garage door. Closed cell foam is the pick against a garage, where R-value per inch and air sealing both matter in a shallow cavity.
Newer houses, where walls are rarely the job. Nearly half of Voorhees was built in the 1980s and 90s, 47.6%, with 38.6% of Winslow Township and 30.8% of Gloucester Township. Those walls hold batts and are not worth opening. What pays there is an addition built to current numbers, or exterior board added when the siding is replaced.
How we do wall insulation in Camden County
Closed walls, through holes. Holes of about 1 to 2 inches go into each stud bay roughly 6 inches below the ceiling, from inside through the finish or from outside after a strip of siding comes off, and each bay is packed to the manufacturer’s density — 3.5 to 4.5 pounds per cubic foot for cellulose, 1.8 to 2.6 for fiberglass — dense enough to resist settling and slow air movement. Bays over headers, under windows and behind cabinets get their own holes, and anywhere old blocking or diagonal bracing interrupts a bay, a second hole goes in below it. An infrared scan confirms every bay is full before the holes are plugged and patched or the siding goes back with its drainage layer. Injection foam is the other through-the-hole method, and before the first hole we settle which product, its data sheet, its R-value per inch, its shrinkage and its cure time.
Open walls. A 3 1/2-inch 2×4 bay takes R-13 or R-15 batts, or about R-24 to R-25 of closed cell foam filling the bay; a 5 1/2-inch 2×6 takes R-20, R-21 or R-23 batts, a full bay of open cell at roughly R-21 to R-23, or about 4 1/4 to 4 1/2 inches of closed cell for R-30 with no board outside. Skip an R-19 batt in a 2×6: compressed into the bay it delivers R-17 to R-18. Batts are cut to fit and split around wiring rather than folded or pinched, corners and headers get filled, electrical boxes on exterior walls are sealed to the air barrier, and the wall behind a tub or shower is insulated while it is open. Foam in living space takes a thermal barrier such as 1/2-inch drywall.
Outside, when the siding is coming off anyway. That is the best chance an old wall gets. Empty cavities get blown first, then R-5 to R-10 of insulating sheathing under the new siding, or R-10 over an already-insulated 2×4 wall. Sheathing and framing get repaired, an air and water control layer goes on with windows and doors flashed into it, jambs and sills are extended for the thicker wall, and furring strips are screwed through the board into the framing to carry the siding. The siding is a siding contractor’s work; the board is ours. Solid brick, stone or block is a different problem: nothing absorbent goes against masonry, so it is board outside under new cladding, or foam on the inside face behind a new stud wall once rain is kept off.
Water is settled before any cavity is filled, because a filled wall dries more slowly — leaks and flashing first, and stucco over wood framing treated as the high-risk cladding it is. Insulation that is wet, settled or rodent-fouled comes out under containment with a HEPA insulation vacuum, mold on framing or sheathing goes to a remediation trade, and pebble-like fill that might be vermiculite is left alone for a licensed asbestos professional. Paid work disturbing paint in a house built before 1978 — which is most of the inner ring — requires a certified firm using lead-safe practices.
What wall insulation costs in Camden County
Most of our projects run between $3,500 and $12,500. Drill-and-fill and injection foam are priced by bay count and access, so a one-story Pennsauken rancher in vinyl siding is a different number from a three-story Collingswood twin whose gable end needs staging. Beyond that the drivers are wall area and height, the material, how many bays are blocked or obstructed, whether holes are drilled inside through plaster or outside behind siding, and the patching either leaves. Exterior board adds thickness, layers, taped seams and every window and door to detail. Electrical work, siding, drywall and lead-safe practices are priced by the trades that carry them. The insulation cost guide sets out our side.
Rebates for wall insulation in Camden County
Wall work usually reaches a program as part of a whole-house scope, and which program depends on the bill. PSE&G carries both fuels in Pennsauken, Collingswood, Haddon Township, Haddonfield and most of Cherry Hill; Atlantic City Electric has the electric in Winslow Township, Voorhees and much of Gloucester Township, with South Jersey Gas on the gas side, and those two townships are split with PSE&G, so the account decides.
PSE&G Whole Home Energy Solutions pays up to $7,500 per project with 0% on-bill repayment of up to $25,000, seven years at $10,000 or less and ten above that or for income-qualified customers, after an assessment by a BPI-certified contractor participating in PSE&G’s program; the free PSE&G Whole Home Energy Assessment is the lighter walk-through. South Jersey Gas Whole Home Energy Solutions publishes its formula: up to $7,500, $2,000 at a modeled 5% saving plus $200 a point above that, capped at half the project cost, with 0% on-bill repayment of $2,500 to $25,000, gas heat and an active account, and a complimentary assessment. Atlantic City Electric Whole Home Energy Solutions reaches $7,500 with 0% financing of $2,500 to $25,000, single-family residences only, and publishes no formula or free walk-through.
Between 250% and 400% of the federal poverty guidelines the work can be free through PSE&G Home Weatherization, the Atlantic City Electric Home Weatherization Program or South Jersey Gas Home Weatherization for Income-Qualified Customers, with New Jersey Comfort Partners at or below 250%, $82,500 for a family of four in 2026. New Jersey’s IRA Home Energy Rebates have not launched, and the federal 25C tax credit ended for anything placed in service after 31 December 2025. Ask any installer, ourselves included, whether they participate in the program you use. Our New York and New Jersey rebate guide covers the rest.
Code and climate in Camden County
Camden County is climate zone 4A, and for walls that changes the vapor rule rather than the R-value. In zone 4, unfaced batts behind painted drywall are allowed and so is kraft facing, with the paper toward the heated room; polyethylene sheeting is not permitted. In the seven zone 5 counties to the north, faced batts or vapor retarder paint are required unless the siding or exterior foam earns an exemption. It is one of the few places where a South Jersey wall is simpler than a North Jersey one.
The R-values are the same statewide. Under the 2024 IECC New Jersey adopted on 17 August 2026, a new wood-framed wall takes R-30 in the cavity, or R-20 cavity plus R-5 continuous, or R-13 plus R-10 continuous, or R-20 continuous alone, with new houses at 3.0 air changes per hour at 50 pascals and windows at U-0.30 in the 4A counties. Cavity and continuous insulation count separately, and a batt squeezed into a shallower bay counts only at what it delivers there. Existing houses fall under the Rehabilitation Subcode: insulation other than foam plastic installed against or within 1 1/2 inches of an interior finish is ordinary maintenance with no permit, while foam plastic needs a permit, which we pull as part of the job.
Towns we serve in Camden County
We insulate walls across Camden County; these eight have pages.
Common questions about wall insulation in Camden County
Can you insulate Camden County walls without removing the drywall?
Yes, in most houses. Cellulose or fiberglass is dense-packed through holes of about 1 to 2 inches in each stud bay, drilled inside through the finish or outside behind a strip of siding, then patched; injection foam goes in the same way. Three things have to be dealt with first: live knob-and-tube wiring, which an electrician replaces, balloon framing that needs blocking top and bottom, and plaster or cement shingles that decide which side we drill from.
Is dense-pack or injection foam better for an older Camden County wall?
Both fill a closed bay through holes and both stand or fall on finding the blocking and confirming the fill. Dense-pack is the long-established drill-and-fill method and handles the irregular bays of a Collingswood or Haddonfield house well. For injection foam we hand you the product data sheet first — R-value per inch, shrinkage and cure time — and it counts as foam plastic in New Jersey, so it needs a permit. Either way an infrared scan checks every bay before the holes are closed.
What R-value do new walls need in Camden County?
For new wood-framed walls the adopted table gives four options statewide: R-30 in the cavity, R-20 plus R-5 continuous, R-13 plus R-10 continuous, or R-20 continuous on its own. No 2×4 cavity reaches R-30 by itself, so a new 2×4 wall pairs batts with board outside; a 2×6 gets there with about 4 1/4 to 4 1/2 inches of closed cell, or with batts plus R-5 outside. Camden sits in zone 4, so unfaced batts behind painted drywall are allowed and plastic sheeting is not.
How much does wall insulation cost in Camden County?
Most of our projects run between $3,500 and $12,500. Closed walls are priced by the number of bays and how easily we reach them, which is why a single-story rancher in Gloucester Township costs less than a tall twin in Collingswood with staging and a plaster interior. Open walls follow area, material and prep. Exterior board carries its own thickness, layers and window detailing. Electrical, siding, drywall and lead-safe work come from those trades on their own quotes.
Free energy audit in Camden County
Before quoting a wall we look inside it: the outlet check on each floor, an infrared scan, the framing and any blocking, the wiring, the siding and sheathing, and every sign of water at flashing, gutters and grade. Then we tell you which of the three routes fits the house, what has to happen first and who does it, and what our part costs. Where the answer is that the walls should stay as they are and the money belongs in the attic or the basement, we say that too.
Call 914-554-2289 or use the contact form, 8am–8pm, seven days. The Home Insulators is family-owned in New Rochelle, NY, with a 100-plus-person in-house crew; we never subcontract.
Get my free estimateor call 914-554-2289, 8am–8pm every day