How Much Does It Cost To Add A New Space To A Home?


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Home Addition Costs

Professionals & Services Cost Guides      Custom Home Builders      Home Addition Costs

Adding a new space to the home is a more complex construction project that involves a variety of elements. To assist in understanding how to calculate the cost of adding a room onto your home, we will discuss the specific costs related to adding a 12x16 foot single-story room, which would add 192 square feet to the home.

Keep in mind that this addition will not be something you can do entirely on your own. This level of construction is best reserved for professional contractors, and you will need a few of them to handle things like carpentry, electrical work, finishing details, and more.

New space addition: The national average for a new space added onto the home is around $23,000, or $124 per square foot. With a return on investment of around $19,000, or 83%, you can trust that the investment is a good one for the sake of resale value, as well.

Item Unit Cost Cost
Addition design services   $2,400-$5,200
Blueprints   $1,200
Architect Services   $1,200-$4,000
Demolition and site prep   $2,000-$18,000
Concrete slab and footings $75 per square yard of concrete $1,000+
Carpentry (Framing, hardware, and other woodwork) $70 per hour plus lumber costs $5,300
Electrical Wiring and Lighting   $65-$85 per hour
HVAC and ductwork $1-$2 per linear foot economy ductwork $192-$384 for ductwork plus hourly labor or job cost
Roofing $80-$100 per square foot shingle cost $450 + labor costs or DIY installation time of 16 hours
Vinyl siding and trim $7 per square foot 3600
Insulation $2 per square foot 825
Interior finishings   $2,411-$3,911
National Average $124 per square foot $23,000

Other considerations and costs

  • Taxes and permit fees are not included in this estimate.
  • Painting and furnishing the space aren’t included, as costs vary significantly based on the type of addition.
  • If your home has a basement, no concrete slab will be needed. This can save you money on materials and labor costs.
  • The type of addition you choose will also impact the cost. Here are some of the most common: mudroom addition ($12,000), home theater addition ($82,000), bathroom addition ($47,000), and bedroom addition ($18,000).

Check out our guide if you need a loan for your home improvement project.

DIY considerations

  • Electrical work, plumbing, HVAC, and other specialty construction should be left to licensed contractors.
  • You can save a significant amount on labor costs by doing some of the work, such as demolition, painting, or even molding and trim work.
  • To avoid causing damage to your home’s structure, hire professionals for all load-bearing demolition needs and concrete slab or foundation work. These are not projects you should take on yourself.


  • Craftsman Estimator Costbook, complete series year 2019.
  • Latest prices found on Home Depot and other vendor Web sites.
  • Literature review of DIY Web sites.
How much does it cost to add a new space to a home in your city?
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Cost by city

  • New York, NY$36,947
  • Bronx, NY$30,360
  • Brooklyn, NY$25,304
  • Philadelphia, PA$31,567
  • Washington, DC$27,392
  • Atlanta, GA$24,783
  • Miami, FL$22,540
  • Fort Lauderdale, FL$23,611
  • Minneapolis, MN$27,698
  • Chicago, IL$32,272
  • Houston, TX$33,287
  • San Antonio, TX$22,344
  • Austin, TX$25,301
  • Denver, CO$21,377
  • Phoenix, AZ$22,553
  • Las Vegas, NV$24,754
  • Los Angeles, CA$27,892
  • San Diego, CA$25,310
  • San Jose, CA$30,572
  • Seattle, WA$22,382

Local costs have been calculated by accounting for labor and material cost differences across different cities. To get accurate cost estimates, indicate yours: