Home Addition Cost, Types & More

The average cost of adding an addition in New Jersey is $86,460. This data is based on actual project costs as reported by ImproveNet.

This figure typically leads homeowners to that daunting dilemma: whether to buy their dream house or transform their current home into that dream. Taking on a home addition is no small fret. There’s a lot to consider and plan for. However, it’s a project that when done right, will provide you and your family with a space all can use and benefit from for years to come. And, according to Hanley Wood’s Cost vs Value report, you’ll also be able to recoup most of what you spend should you decide to sell. To ensure your New Jersey home addition project turns out just the way you want it to, we’ve broken down the important items you should know before starting, such as:

  • The different home addition types
  • Home addition costs
  • And most importantly – how to plan for your home addition

If you’ve been saving ideas from Houzz for a while and are ready to take your home addition concepts to the next phase, keep reading.

Home Addition Types 

Two Story Extensions – Two Story Extensions are designed to enlarge a home which has enough height but could use some extra length or width. They can be built on any side of the house, and room size is dependent on available space and your wants.

Exterior Renovations

Home Addition Extension in Westfield, NJ

Second Story Extensions – Second Story Extensions are for homes with one level that would like to add a second story to their home. A second story addition cost is greater because to achieve this project, the entire roof is removed from the home. The second story extension is added on, followed by the roofing installation as well as the repair of HVAC, air, electrical, and anything else that had to be removed to put the extension in place.

In-law Additions – In-law home additions are built onto any side of your home and are usually built to include a kitchenette, living room, master bedroom, closets, and a bathroom.

In-Law Addition

In-Law Addition

Kitchen Extension Addition – Often times homeowners feel that their kitchen is too small. They want to stay in their home and expand the space. With a kitchen addition, a homeowner can add around 200 additional square feet to their kitchen.

Kitchen Addition

Montclair Kitchen Addition

Bedroom Additions – A bedroom addition “home extension” will be built onto an exterior wall of your choice with a crawl space foundation. Roofing and Siding will be matched to your existing house.

Bathroom Additions – If your family is growing and sharing one or two bathrooms isn’t cutting it anymore, bathroom additions can be built onto the exterior wall of your choice.

Family Room Addition – The existing roofing and siding will be matched to your current home and a family room addition will be built off an existing exterior wall of your choice, crawl space foundation.

Home Addition with Custom Woodwork

Family Room Addition in Westfield, NJ

Sunroom Additions – Aside from the natural lighting a sunroom addition provides, it can also be a large family room or entertaining area for when you have guests over.

interior renovations with sunroom home addition

Front Porch Addition – A porch addition will enhance your curb appeal as well as entertaining possibilities.  Porch Additions are generally built onto the front of the home; however, they are also able to be added to the rear of the home.

Wood beam exterior renovation

Front Porch Addition

Garage Additions (1-3 Car Plans) – A Garage Addition can be built as an addition onto your home which is attached to the side of your home, or it can be built as a detached Garage Addition.  Garage Additions can be built to accommodate between one and three cars.  The roof and sides will be built to match your home roof and walls.

Garage Conversion – Convert your existing garage into a room with a garage conversion.  Removal of existing garage door, installation of trim, drywall, flooring, interior door, siding, windows, and paint.

Bonus Room Above Garage Additions – Building a Room Over your Garage can be the ticket to a larger home.  The existing garage roof will be removed, and a master suite will be built above the garage.

How Much Does A Home Addition Cost?

There’s no straight forward number for each project type because there are so many different factors that play a part in determining the final cost of a home addition. However, the most important rule of thumb to go by is; the larger you go, the more expensive the project will be. According to Home Advisor, some other important factors include necessary services, like:

  • Professional services to ensure the design of the new addition looks good with the interior and exterior style of the rest of the home. This typically accounts for 10% to 17% of the total project budget.
  • Excavation, demolition, and site-preparation costs vary depending on the professional and amount of work that needs to go into the prepping.
  • Pouring concrete footings and a slab foundation. This costs an average of $75 per cubic yard.
  • Roofing for a new addition averages $80–$100 per square foot for asphalt shingles and galvanized metal flashing. If you go with metal roofing or slate the pricing increases.
  • Flooring costs will add to your home addition cost. Popular choices include ceramic tile (AVG: $1,640), carpeting (AVG: $1,490), laminate wood (AVG: $2,748), vinyl/linoleum (AVG: $1,185), natural stone tile (AVG: $1,826) or wood flooring (AVG: $4,396).
  • Tying into the existing HVAC system varies in cost, but the average cost for installing ducts and vents is $1,050.

If you’d like to get a home addition cost estimation, head over to Home Advisor’s True Cost Guide.


Planning Your Home Addition Project

Plan your build

This means starting off knowing the type of home addition you want and planning the design, floor plan, and budget specifically for it. Most homeowners think they approach this during the concept phase, however, once they speak to a home addition contractor they find that it’s more involved than expected. If you’re not sure which project type fits your needs, consult with a professional. They will review your wants and goals to make suggestions that fit your family and home.

Choose the materials

The best home additions look like part of the original structure. To ensure yours falls in that category, speak with a professional about roof and foundation, choosing finishes, and integrating your home’s operational systems. Here’s a checklist of what to bring up during a call or meeting with a home addition Contractor:

  • Materials & Finishes
  • Designing a Roof Addition
  • Tips for Insulation
  • Utilities and Systems
  • Blending an Addition
  • Laying the Foundation
  • Choosing Windows
  • HVAC Options

Hiring the Best Home Addition Contractor in Your Area

An addition is a major undertaking that involves tradespeople, specializing in everything from roofs to foundations. To ensure that your project starts and ends well, review the following with your Contractor:

  • What specialty tradespeople are on their team?
  • How will construction be overseen?
  • Relay your expectations and ask how they’ll be addressed throughout the project

When it comes to the place your family calls “home”, the difference is in the details, and the company executing them.

Hire the right company for your project by asking the questions in our guide.