ADU Builders in New Jersey

    Garden State ADU is a licensed New Jersey home improvement contractor (NJ HIC #13VH13918800). We build accessory dwelling units, in-law suites and conversions in Central Jersey, and for the rest of the state we match homeowners with an ADU builder who works in their area.

    Either way the first step is the same, and it is an easy one to skip: we read your town's zoning before anyone draws anything.

    Why the search for an ADU builder starts with your town

    It is tempting to hire an ADU contractor and let them worry about the rules. In New Jersey that is a risk, because there is no statewide ADU law here. Each of the state's municipalities writes its own zoning ordinance, and the answers are far apart. A few towns permit an accessory dwelling unit on an ordinary residential lot. Some permit only a suite for a family member. Many have written nothing at all, which usually means a detached backyard unit needs a variance from the zoning board.

    So the useful question is not only who builds ADUs near you. It is what your town will let you build, and then who builds that. A builder can give you a fair price for a detached cottage that your zoning board will never approve. We would rather you knew the answer before you paid for plans.

    Our town-by-town guide to New Jersey ADU rules shows what we have verified so far. The free zoning check covers your own address, including towns that are not in the guide yet.

    How the match works

    1. 1

      You send your address

      Street address and ZIP, plus what you are hoping to build and for whom. It takes about a minute and costs nothing.

    2. 2

      We read your town's rules

      You get an email with a first read: whether your municipality has an ADU ordinance, a family-suite provision, or neither, and what that means for a detached unit, an attached suite or an addition. If we have not read your town's code closely yet, we tell you that instead of guessing.

    3. 3

      A person follows up

      Within 1 to 2 business days you hear from Osama, who owns the company. This is where the lot itself comes in: your zone, your setbacks, what already sits on the property.

    4. 4

      We build it, or we match you

      If your lot is in Middlesex, Mercer, Monmouth or Somerset County, we can design, permit and build it ourselves. If it is anywhere else in New Jersey, we introduce you to a builder who works in your area, and we pass along the zoning read so you do not start from zero with them.

    We are plain about the business side. When we match you with a builder outside our area, we share your project details with that builder so they can contact you, as our privacy policy describes. You do not pay us for the zoning check or for the introduction. The builder may pay us a referral fee if you hire them, and that does not change what you pay the builder.

    What to check before you hire any ADU builder in New Jersey

    A registration number you can look up

    New Jersey's Contractor's Registration Act requires home improvement contractors to register with the Division of Consumer Affairs and display their registration number. Ask for it before anything else, and look it up yourself. Ours is on every page of this site.

    Who applies for the construction permit

    Under the state's Uniform Construction Code, a permit has to be issued before the work starts. Ask who is filing the application and whose name goes on it. A builder who suggests skipping the permit is telling you how the rest of the job will go.

    A zoning answer before any design money

    Whether you may build a second unit at all is a zoning question, and it comes before floor plans. If a builder wants a design deposit before anyone has read your town's ordinance against your lot, you are paying to find out something that could have been checked first.

    A written scope and a written price

    The contract should say what is being built, what is not included, and what the payment schedule is tied to. Site work, utility connections and permit fees are the items that most often turn out to be missing.

    ADU builders by region, and what each town allows

    These are the towns we have written up so far. Each link goes to that town's page, with the ordinance, the conditions and the questions people ask most. If your town is not listed, the free check still covers it.

    Central Jersey

    This is where we build ourselves: Middlesex, Mercer, Monmouth and Somerset counties. If your lot is here, the company that reads your zoning is the company that builds the project.

    • ADU builder in PrincetonMercer County · Permitted by-right

      Yes. Princeton's code lists an accessory dwelling unit as a permitted accessory use in its residential districts (R-A through R-H), one per lot, with no owner-occupancy requirement. It is among the most permissive ADU ordinances in New Jersey.

    • ADU builder in TrentonMercer County · Ordinance on the books, approval route unconfirmed

      Trenton's land development code has an accessory dwelling unit section with real standards in it: one unit per lot on at least 4,000 square feet, up to 800 square feet and 40% of the main house, two bedrooms, and no extra parking space. We have not yet confirmed which zoning districts the section applies to or what approval it takes.

    • ADU builder in Lawrence TownshipMercer County · Permitted with conditions

      Yes, but for family. Lawrence Township permits an accessory apartment in seven residential zones, and the ordinance requires its occupant to be a family member of the owner or a caretaker for the owner or the owner's family.

    • ADU builder in Red BankMonmouth County · Permitted by-right

      Yes. As of June 2026, Red Bank permits one ADU per lot in eight zoning districts, one of the newest ADU ordinances in New Jersey. Units are capped at 800 square feet and two bedrooms, with owner-occupancy required.

    • ADU builder in MiddletownMonmouth County · Permitted with conditions

      Yes, via two distinct paths: an affordable accessory apartment program (with grants up to $60,000 but a 10-year rent restriction), or a family-only mother-daughter suite under § 504-203.

    North Jersey

    Most of the towns in our guide that have written an ADU ordinance are here, in Essex, Hudson, Bergen and Union counties. We run the zoning check, then match you with a builder who works in your county.

    • ADU builder in Jersey CityHudson County · Permitted by-right

      Yes. Jersey City's zoning code lists one accessory dwelling unit per lot, in a detached accessory structure, as an accessory use in the RH-1, RH-2, R-1, and R-2 zones, regardless of lot size and in addition to the units in the main building.

    • ADU builder in MaplewoodEssex County · Permitted by-right

      Yes. Maplewood permits one ADU per lot as a permitted use in the R-1-4, R-1-5, R-1-7, and R-2-4 zones, capped at 40% of the principal dwelling or 800 square feet, with owner-occupancy required.

    • ADU builder in MontclairEssex County · Permitted by-right

      Yes. Montclair permits one ADU as an accessory use on lots with one- or two-family homes in the R-O, R-O(A), R-1, and R-2 zones under its March 2023 ordinance.

    • ADU builder in South OrangeEssex County · Permitted by-right

      Yes. South Orange permits one ADU per lot on single- and two-family properties in the RA-50, RA-60, RA-75, RA-100, and RB zones, sized between 350 and 750 square feet.

    • ADU builder in TeaneckBergen County · Permitted by-right

      Yes. Teaneck permits ADUs in the R-S, R-M, and B-R zones under Ordinance 6-2025, adopted February 2025, one of the newest ADU ordinances in Bergen County.

    • ADU builder in Union TownshipUnion County · Permitted with conditions

      Yes, with real limits. Union Township permits one interior ADU in owner-occupied single-family homes in the RA and RB zones on lots of at least 5,000 square feet, but detached units, garage conversions, and basement ADUs are not allowed.

    • ADU builder in East OrangeEssex County · Permitted with conditions

      Yes, conditionally. East Orange has an ADU ordinance on the books, but many projects require Planning Board approval, a discretionary step that towns like Maplewood and Montclair don't impose.

    • ADU builder in NewarkEssex County · Permitted with conditions

      Yes, within limits. Newark's zoning code permits ADUs with owner-occupancy on lots of at least 5,000 square feet, attached units of 400 to 600 square feet, and detached rear-yard units up to 700 square feet.

    The Shore

    The shore towns in our guide each attach their own conditions, such as two extra off-street parking spaces in Bradley Beach and no short-term rentals in Asbury Park. We check the ordinance first, then match you with a builder who works at the shore.

    • ADU builder in Asbury ParkMonmouth County · Permitted by-right

      Yes. Asbury Park permits ADUs on legal one- and two-family lots in its residential zones and the B zone, effective April 2024. Owner-occupancy is required and short-term rentals are prohibited.

    • ADU builder in Bradley BeachMonmouth County · Permitted with conditions

      Yes, with strings attached. Bradley Beach permits accessory dwelling units, but requires two additional off-street parking spaces and imposes strict occupancy rules, a high bar on the borough's compact shore lots.

    • ADU builder in Cape MayCape May County · Permitted with conditions

      Yes, through the affordable housing program. Cape May permits accessory apartments within or attached to a principal dwelling under its affordable housing regulations, a narrower path than a market-rate ADU.

    When the answer is not a detached ADU

    Most of the people who write to us want room for a parent or an adult child, and most of them live in a town with no ADU ordinance. For them the project that gets built is usually one of these, because each stays part of one legal residence:

    If a second unit already exists on your property without paperwork, the question is different, and we cover it in legalizing a basement apartment in NJ.

    FAQ

    Questions about hiring an ADU builder in New Jersey.

    No. We build in Central Jersey ourselves, which means Middlesex, Mercer, Monmouth and Somerset counties. Everywhere else in the state we still run your zoning check, and then we match you with a builder who works in your area. We say which one applies to you in our first reply.

    Start with what your town allows.

    Free zoning check on your address, then a builder who works where you live.

    Where we build

    We build in Central Jersey ourselves: Middlesex, Monmouth, Mercer, and Somerset counties. Anywhere else in New Jersey we still run your zoning check and can connect you with a builder in your area, and we vet anyone before we refer you.

    What you get in about a minute

    Subject: Your NJ zoning check: Middletown

    Middletown has two paths to a second unit: a family-only suite for a relative, and an accessory apartment that can be rented under the township's own conditions. For most families the useful path is the mother-daughter provision (Ordinance #504-203).

    Then a personal reply from Osama within 1 to 2 business days.

    For a quick 10-minute call. No texts, no spam.

    By submitting, you agree we may contact you by phone or email about your request, and that if we do not build in your area we may share it with a builder who does, after we vet them.

    Statewide NJ · NJ HIC #13VH13918800