A garage with an apartment above costs $200 to $350 per square foot, or $80,000 to $300,000, by HomeGuide's national figures. In New Jersey, local zoning decides whether you may build one at all, so that is the first thing to check.
Every dollar figure on this page is a national figure published by HomeGuide (read October 2026), not a price from us. HomeGuide publishes no figure for New Jersey or Newark, so we do not claim one. On a real job, the price moves with access down a narrow driveway, any old garage to remove, footings deep enough for frost and the finish you pick.
How much does a garage with an apartment above cost?
A garage with an apartment above costs $80,000 to $300,000 by HomeGuide's national figures, or $200 to $350 per square foot. HomeGuide lists $80,000 to $140,000 for a 20 x 20 footprint and $115,000 to $200,000 for 24 x 24. A prefab garage with an apartment costs $60 to $100 per square foot, or $35,000 to $100,000. The kitchen, bathroom and stairs are what make the living space costly.
Can I build an ADU over or in my garage in New Jersey?
Whether you can build an accessory dwelling unit, or ADU, over or in a garage depends on your town's zoning. We could not confirm any New Jersey law that requires towns to allow ADUs; bills on the subject have been introduced in the Legislature. Many towns limit a lot to one home, or allow a second unit only in certain zones. We check your town's zoning for your address before any drawings.
Can I build a second story over my existing garage?
A second story or room over an existing garage is possible if the walls and foundation can carry it and zoning allows the height. HomeGuide puts a second story over a garage at $60,000 to $200,000 or more. Many older garages in Newark and the nearby towns were built on thin slabs with no real footings, so the old garage is often taken down and rebuilt with a stronger frame.
Can my garage foundation hold a room on top?
Often the garage foundation cannot hold a room on top without being reinforced, especially on garages from the 1920s to the 1950s. An engineer checks the footings and the soil, and the plans may call for new, deeper footings or a new foundation. In North Jersey those footings also have to go below the 3-foot frost depth the state code lists for the northern counties.
How much does it cost to convert a garage into a bedroom or living space?
Converting a garage to living space costs $5,000 to $50,000 or more, or $50 to $200 per square foot, by HomeGuide's national figures. A bedroom conversion runs $5,000 to $17,000, an office $5,000 to $10,000, and a garage-to-apartment or ADU conversion $20,000 to $100,000 or more. A one-car conversion costs $5,000 to $20,000 or more and a two-car $10,000 to $50,000 or more.
Does converting a garage hurt resale value?
Converting a garage can lower resale value in some places. HomeGuide says converting a garage in a cold region or an area with limited parking may devalue the property. Newark is both, so think about who will buy the house later. Picture the next buyer on your block: an extra legal bedroom may appeal to them, but losing the only spot off the street in the North Ward or the Ironbound may not.
Do I have to replace or raise the slab when converting a garage?
Usually you do not need to replace the slab, but it must be leveled, sealed and insulated. Garage slabs slope toward the door and often sit below the house floor, and older ones may have no vapor barrier under them. The common fix is a moisture barrier, rigid insulation and a new subfloor on top, which also brings the floor up toward the house level.
What does a bedroom in a garage need to pass inspection?
A bedroom in a converted garage needs an egress window or door, heat, insulation that meets the energy code, outlets and smoke and carbon monoxide alarms. The garage door opening is framed in as a wall. In North Jersey winters, heat is the part owners often underestimate. HomeGuide puts a ductless mini split at $2,500 to $6,000 for one zone on its garage conversion page.
Can I rent out an apartment above my garage?
You can rent out an apartment over your garage only if the town approved it as a separate dwelling. Zoning, the certificate of occupancy and local rental rules all apply. Some New Jersey towns register or inspect rental units, but we could not confirm the rules for each town, so check with your municipality before you sign a lease.
Thinking about a garage on your lot? We come out, measure, check the driveway and whatever is standing there now, and send a written quote. Call or text (917) 909-5756.