An addition is the biggest project most homeowners ever take on short of building new, and the price swings more than any other kind of job. A small bump out and a full second story are both "additions", but one can cost several times the other. Below are the real ranges for each type in Passaic, Bergen and Essex Counties, the costs that sit outside the construction price, and honest timelines from first drawing to moving in.
The short answer
In North Jersey, a bump out costs about $55,000 to $160,000, a one story rear or side addition about $100,000 to $275,000, a two story addition about $210,000 to $450,000 or more, a primary suite addition about $150,000 to $350,000, and a full second story addition about $250,000 to $600,000 or more. These are all in construction prices. They cover the foundation, framing, the roof tie in, matching siding, windows, insulation, drywall, electrical, plumbing, extending your heating and cooling, and finishes. Design, engineering, permits and contingency come on top.
Cost by type and county
| Addition | Passaic County | Bergen County | Essex County |
|---|---|---|---|
| Bump out50 to 200 sq ft | $55K to $130K | $60K to $160K | $60K to $140K |
| One story addition300 to 600 sq ft | $100K to $225K | $110K to $275K | $120K to $250K |
| Two story addition400 to 600 sq ft footprint | $210K to $400K | $250K to $450K+ | $230K to $420K |
| Second story addition1,000 to 1,400 sq ft | $250K to $500K | $300K to $600K+ | $275K to $550K |
| Primary suite addition400 to 700 sq ft | $150K to $300K | $180K to $350K | $160K to $320K |
These are typical ranges for quality work from a licensed builder, not quotes. Your price comes from a written estimate once we have seen your house and your plans.
Each type of addition, explained
Bump out (50 to 200 sq ft)
A bump out pushes one wall out 3 to 10 feet to make room for an island, a soaking tub, a double vanity or a breakfast nook. It is small, but it still needs a foundation, a roof tied into the house, matching siding and a permit, and those costs do not shrink with the room. A kitchen or bathroom bump out also moves plumbing, gas and venting.
What we typically see: a 120 to 150 square foot kitchen bump out with new cabinetry tied in lands around $90,000 to $150,000. A simple bump out with no plumbing, like a dining nook, can start around $55,000 to $75,000.
One story rear or side addition (300 to 600 sq ft)
A new family room, bedroom or office on its own foundation, with a roof tied in and heating, cooling and electrical extended from the house.
What we typically see: a 400 square foot rear family room runs about $140,000 to $180,000 in Passaic, $150,000 to $200,000 in Bergen and $145,000 to $190,000 in Essex. Adding a half bath or a wet bar adds about $20,000 to $40,000.
Two story addition (400 to 600 sq ft footprint)
A new foundation with two finished floors, often a family room below and a primary suite above, tied into the existing roof and stairs. Because both floors share one foundation and one roof, it costs less per foot than a bump out, but it is the biggest tie in to your house short of a full second story.
What we typically see: a 20 by 24 foot two story addition (about 960 square feet over both floors) with a family room down and a primary suite up runs about $220,000 to $340,000 in Passaic, $260,000 to $380,000 in Bergen and $240,000 to $360,000 in Essex. The upstairs bathroom is what swings the price.
Second story addition (1,000 to 1,400 sq ft)
Building a full floor on top of a ranch or a Cape. The existing foundation and walls are checked by a structural engineer, the roof comes off under weather protection, and a new floor, stairs, second floor and roof go on. The new floor often holds three bedrooms and one or two bathrooms. Many families move out for part of the job. See our second story additions page for how we run them.
What we typically see: a 1,200 square foot second story with three bedrooms and two bathrooms in mid to upper finishes runs about $320,000 to $450,000 in Passaic, $375,000 to $525,000 in Bergen and $350,000 to $480,000 in Essex. Reinforcing the existing structure can add $20,000 to $60,000. A quote far below these ranges for a full second story usually means major parts of the job have been left out.
Primary suite addition (400 to 700 sq ft)
A new bedroom with a full bathroom and a walk in closet, usually as a ground floor rear addition. The bathroom is the variable. It brings tile, plumbing runs, waterproofing, ventilation, and often its own heating and cooling zone or an electrical service upgrade.
What we typically see: a 500 square foot suite with a well finished bathroom and a walk in closet runs about $170,000 to $240,000 in Passaic, $200,000 to $280,000 in Bergen and $185,000 to $260,000 in Essex. That bathroom has a tiled shower, freestanding tub and double vanity.
| Project | Passaic County | Bergen County | Essex County |
|---|---|---|---|
| Rear family roomAbout 400 sq ft | $140K to $180K | $150K to $200K | $145K to $190K |
| Two story addition20 × 24 ft, family room down, primary suite up | $220K to $340K | $260K to $380K | $240K to $360K |
| Second storyAbout 1,200 sq ft, 3 bedrooms, 2 bathrooms | $320K to $450K | $375K to $525K | $350K to $480K |
| Primary suiteAbout 500 sq ft with a full bathroom and walk in closet | $170K to $240K | $200K to $280K | $185K to $260K |
Why online calculators look lower
If you have priced an addition online, you have probably seen per square foot figures well below the ranges on this page. Those numbers usually cover only the shell of the new room. They tend to leave out the parts that make an addition real. Those include design and engineering, permits, tying the new structure into your house and roof, extending your heating and cooling, matching the siding and trim, and the finishes inside. A builder's written estimate includes them, which is why it is the only number worth planning around.
What is not in the construction price
The ranges above cover building the addition. Plan for these as well:
| Item | Typical cost |
|---|---|
| Architect and design | 8 to 15% of construction, or $8K to $25K |
| Structural engineerRequired for a second story | $2K to $5K to assess; $1.5K to $6K for stamped drawings |
| PermitsBuilding, subcodes, plan review and certificate of occupancy | $2.5K to $6K; more if a zoning variance is needed |
| Contingency | 10 to 15%; 15 to 25% for a second story |
| A kitchen inside the addition | +$30K and up |
| A full bathroom inside the addition | +$20K and up |
Why prices differ by county
Bergen County
Bergen sits at the top of the range. Higher labor costs and careful town plan reviews push every type of addition up. We've built all over Bergen County since 1990. See home additions in Bergen County.
Essex County
Essex has the widest spread from one town to the next. Some towns price close to Bergen, and historic district reviews in some towns add time before work can start. We've built all over Essex County since 1990. See home additions in Essex County.
Passaic County
Passaic runs a little below Bergen overall, with the higher end of the range in its larger suburban towns. We've built all over Passaic County since 1990, from our Clifton headquarters. See home additions in Passaic County.
Realistic timelines
The 2 to 4 months you often hear is the construction time for a bump out or a smaller one story addition. The full project takes longer, because design, engineering and town permits come first.
| Addition | Design and permits | Construction | Total |
|---|---|---|---|
| Bump out | 6 to 10 weeks | 8 to 16 weeks | 4 to 6 months |
| One story addition | 2 to 3 months | 3 to 5 months | 5 to 8 months |
| Two story addition | 2 to 4 months | 4 to 7 months | 6 to 11 months |
| Primary suite | 2 to 3 months | 4 to 6 months | 6 to 9 months |
| Second story addition | 3 to 6 months | 4 to 8 months | 9 to 18 months |
Before construction starts, you get a written schedule for your addition, and we keep you posted if anything shifts.
Additions we have built
Here is one of our additions from start to finish. It is a one story addition that turned an old wraparound porch into new office space for a medical practice.
Our medical office addition, before and after, from the same corner.
From the old porch, through the new foundation, to the finished addition.
“I hired Omar to build my addition a few years back but am I writing my review now since it was kindly requested. After hurricane Ida I called Omar and thanked him for the work he had done 7 years ago because during the hurricane I was one of the only houses in my neighborhood who didn't have a basement flood thanks to Omar's expertise in building! I recall that when building my house he had told me that he was inserting drains all around the basement to prevent flooding, without me even asking for it! In general, whenever I call Omar now, even years later, he always answers and offers his advice, expertise, and help. Building with Omar is insuring your home for life!!”Rivky Schwartz, Google review
See more of our work on the home additions page and in our project portfolio.
What to ask any builder
Whoever you hire, these are the things that protect you on a project this size:
- A registration and insurance you can verify. New Jersey home improvement contractors must be registered with the state Division of Consumer Affairs. Check the number, and ask for current liability and workers' compensation certificates. Ours is NJ #13VH09340700.
- An itemized written proposal once the design is done, not a guess per square foot.
- Stamped structural drawings from a New Jersey licensed engineer or architect for anything that carries load.
- Permits pulled by the contractor. We handle the permits for our clients. A contractor who asks you to pull them yourself is worth a second look.
- A written allowance schedule for tile, fixtures, cabinets and flooring, so "midrange" has a dollar amount attached.
- Payments tied to milestones, such as foundation, framing, rough in, finishes and certificate of occupancy, not half up front.
A quote that comes in far below the ranges on this page almost always leaves something out, like permits, engineering, heating and cooling, matching the exterior or finish allowances, and it comes back later as change orders. Our guide on how to choose a home addition contractor in North Jersey covers the red flags in detail.
Why homeowners choose us
- 35+Years building, since 1990
- 4×Best of Houzz
- 5.0Customer rating
- Our ownCrew, not subcontracted
We are licensed and insured (NJ #13VH09340700), and we have built additions, second stories and custom homes across North Jersey since 1990. We also work in Morris, Hudson and Sussex Counties. See all the areas we serve.
How to get an exact price
- Tell us what you want to add. Call 973-418-6375 or use the form below and tell us if you want more living space, a bigger kitchen, a primary suite or a whole second floor.
- We visit your house and lot. We look at the structure, the setbacks and what your town will require, and talk through options and your budget.
- You get a free written estimate. It spells out the scope, what is included and what is not, so there are no surprises later.
Planning a kitchen or bathroom inside the addition? See our kitchen and bathroom cost guides.
