Basement finishing in North Jersey

The EPA recommends testing for radon on the lowest lived-in level, so a basement that hasn't been tested should be tested before it is remodeled; fixing a radon problem is usually easier and cheaper before the basement is finished.¹³ NJDEP rates a town Tier 1 when at least 25 percent of tested homes measure 4 picocuries per liter or more, Tier 2 at 5 to 24 percent and Tier 3 below 5 percent, each based on at least 25 homes tested.³ None of Bergen County's 70 municipalities or Essex County's 22 is in NJDEP's Tier 1 for high radon potential; every one is rated Tier 2 (moderate) or Tier 3 (low).³ That doesn't make a test optional; it means the result is harder to guess. The EPA's guidance is to fix your home if radon tests at 4 picocuries per liter or higher, and to consider fixing it between 2 and 4.¹⁴

By New Jersey law, every business and professional that tests for radon or installs radon mitigation must be certified by NJDEP.⁴ Department of Community Affairs rules require builders to include radon-resistant features in new homes built in Tier 1 areas.¹⁵ No Bergen town falls under that rule, so an older house here almost never has the pipe. Ask whether it can be roughed in while the ceiling is open, even if your first test comes back low.

Under New Jersey law, a seller whose home has been tested for radon must give the buyer, when the contract of sale is signed, a copy of the test results and evidence of any mitigation.¹⁵ NJDEP says 75 to 80 percent of the roughly 60,000 radon tests done in New Jersey each year are done as part of home sales.¹⁵ A recent result in your file is one less question when the house is sold.

New Jersey's Division of Codes and Standards says finishing an existing basement is an alteration under the Rehabilitation Subcode, and nothing requires raising the existing ceiling to 7 feet just because the space is being finished.¹¹ For comparison, the model code for new houses asks for more. The 2021 IRC requires habitable space and hallways, including the parts of a basement that contain them, to have a ceiling at least 7 feet high, and bathrooms and laundry rooms at least 6 feet 8 inches.¹⁶ In a postwar basement, ducts and steel beams are what usually set the real headroom.

When an alteration creates a bedroom below the fourth floor, it needs a window or exterior door that meets the subcode's escape-opening requirements, plus a hard-wired smoke alarm in the bedroom and a second one near it.¹² Under that code, an escape opening needs a net clear opening of at least 5.7 square feet, at least 24 inches high and 20 inches wide, with its bottom no more than 44 inches above the floor.¹⁶ The original hopper windows in a block basement are far too small, so a bedroom means cutting the opening down and setting a well outside. An escape window whose bottom sits below the ground outside needs an area well of at least 9 square feet, at least 36 inches out from the wall and 36 inches wide, big enough for the window to open fully.¹⁶

Before turning basement space into living space, the EPA advises checking it for leaks and other signs of moisture and fixing any moisture problem first, because damp basements promote mold and other biological growth.¹³ The EPA warns that carpet on a basement slab can stay damp from water or vapor coming up through the concrete, or from room moisture condensing on a slab that is colder than the air, and either can lead to mold.¹³

Building America advises keeping fiberglass batts and cellulose out of contact with foundation walls, and not putting polyethylene sheeting, vinyl or foil wallpaper, or epoxy, oil or alkyd paint on the inside of basement walls, because they trap moisture.¹⁷ ENERGY STAR's guidance for existing homes, based on the 2021 IECC, is R5 insulating sheathing or R13 batts on basement walls in climate zone 3, R10 sheathing or R13 batts in zones 4A and 4B, and R15 sheathing or R19 batts in zones 4C and 5 through 8.¹⁸ Since the table turns on climate zone, ask which zone and wall assembly the quote assumes and confirm both on the permit drawings.

Under New Jersey's flood hazard rules, a regulated flood hazard area and riparian zone exist along every regulated water that drains 50 acres or more.¹⁹ If your street floods, ask the town's floodplain administrator before finishing anything below grade.

Bergen County's Home Improvement Program won't pay for basement or attic improvements other than infrastructure such as plumbing, heating and HVAC.²⁰ A Bergen County loan can still cover a new boiler, wiring or plumbing that happens to live in the basement, but not the finished room itself. Bergen County's Home Improvement Program gives qualified low- to moderate-income owner-occupants an interest-free loan with no monthly payments, repaid when the home is sold or the title transfers.²⁰

More than one in four adults 65 and older fall each year.²¹ A steep, narrow cellar stair in a postwar house is a likely spot for one. Finishing the basement is the time to add a rail on the open side, light you can switch on from either end and nosings that stand out from the tread. NAHB's Certified Aging-in-Place Specialist (CAPS) credential trains remodelers in home modifications for aging in place.²²

Calling the number on this page puts you through, on a recorded line, to one independent company that handles basement finishing in the North Jersey area. What gets built, when and for how much is up to you and that company.

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Check the company's state registration before paying a deposit. New Jersey's Contractors' Business Registration Act requires every home improvement contractor business, from a sole proprietorship up, to register with the Division of Consumer Affairs every year before selling or making home improvements, unless the law exempts it.²³ The Division of Consumer Affairs' License Verification System is a real-time lookup; its Business Search finds home improvement contractor businesses by business name, license number or city and lists each one's registration number, license type, status and city.²⁴ Check a New Jersey license

Ask who will file the building, plumbing and electrical permits, and whose name goes on each. Teaneck's Building Department warns homeowners not to let a general contractor do licensed trade work under a permit pulled in the homeowner's name.²⁵