More Adding Living Space: Sunroom ·Garage Conversion ·ADU ·Basement Finishing
A home addition costs $22,000 to $100,000 or more in 2026. Most people pay about $51,000, or $80 to $500 per square foot. How you add space and what room you build set the price. If you like where you live but need more room, adding on is often cheaper than moving. It’s still one of the bigger projects a homeowner takes on.
What you pay for
An addition is like building a small house onto your own. You pay for the foundation, framing, roof and exterior, the inside finishes, and the plumbing, wiring, heating and cooling. Design and permits come on top.
The part people underestimate is joining the new space to the old. Tying the new foundation, roofline, and heating and cooling into your house adds cost. A simple price per square foot won’t show it.
What changes the price
How you add space matters most:
- A bump-out (a small addition that pushes one room outward) costs $20,000 to $40,000.
- A sunroom costs $80 to $250 per square foot.
- A standard room built on the ground costs $150 to $350 per square foot.
- A second story costs $300 to $500 per square foot.
The room you add matters next. A bedroom or family room is the low-cost end. Add plumbing for a bathroom or kitchen, and the price per square foot climbs fast. You pay for fixtures, waterproofing, and the pipes that bring water in and take it away. A bathroom addition costs $250 to $500 per square foot. Build the room that meets a real need in your daily life or adds to your home’s value.
Should you build out or up?
Building out, on the ground, costs less per square foot but uses up yard space. Building up, with a second story, saves your yard but costs more. The house below must be made stronger to carry the new floor, and you may need to move out during the work. The right choice depends on your lot, your budget and how much yard you’re willing to give up.
How to spend less
- Build out, not up, if your lot has room.
- Keep kitchens and bathrooms near your existing pipes. Moving plumbing far adds cost.
- Keep the roofline simple to hold down framing costs.
- Don’t over-improve. Keep the project in line with what homes in your neighborhood are worth.
If money is tight
- Cheapest safe way
- A small bump-out ($20,000 to $40,000) or a simple ground-level bedroom with basic finishes costs the least. Building out costs less per square foot than building up.
- What can wait
- Higher-grade finishes. The cheapest additions use basic finishes, and the grade of materials you pick can change the total a lot.
- Don't skimp on
- Permits and inspections. Additions need them to be legal and sellable, and a second story needs the house below strengthened to carry it.
| Item | Typical range | Notes |
|---|---|---|
| Foundation and structure | $5,000 – $25,000 | – |
| Framing, roof and exterior | $10,000 – $40,000 | – |
| Inside finishes | $8,000 – $35,000 | – |
| Plumbing, electrical, heating and cooling | $5,000 – $25,000 | – |
| Design and permits | $2,000 – $10,000 | – |
| Option | Typical range | Notes |
|---|---|---|
| Bump-out or small addition (build out) | $20,000 – $40,000 | – |
| Standard room (build out) | $150 – $350 / sq ft | – |
| Second story (build up) | $300 – $500 / sq ft | – |
| Bathroom addition | $250 – $500 / sq ft | – |
| Sunroom | $80 – $250 / sq ft | – |
What affects the price
- Building out or up Building out, on the ground, costs $80 to $350 per square foot. Building up with a second story costs $300 to $500 per square foot, because the house below must be made stronger to carry it.
- Size A bigger addition costs more in total, but the price per square foot often drops as it gets larger.
- Room type Bedrooms and living space cost the least. Kitchens and bathrooms cost more because of the plumbing and fixtures.
- Connecting to the house Joining the new foundation, roofline, and heating and cooling to your house adds real cost.
- Finishes and region The grade of materials you pick and local labor rates can change the total a lot.
Home addition cost by state
Where you live can change the price as much as the options you pick. Labor is a big part of the bill, and construction workers are paid more in some states than others. A typical home addition job costs about $25,700 to $117,000 in Hawaii (17% above the U.S. average). In Arkansas, it costs about $18,700 to $85,000 (15% below the U.S. average).
See the typical cost in all 50 states and D.C.
| State | Typical range |
|---|---|
| Alabama | $19,100 – $87,000 |
| Alaska | $25,300 – $115,000 |
| Arizona | $20,900 – $95,000 |
| Arkansas | $18,700 – $85,000 |
| California | $24,600 – $112,000 |
| Colorado | $22,000 – $100,000 |
| Connecticut | $23,500 – $107,000 |
| Delaware | $21,600 – $98,000 |
| District of Columbia | $23,800 – $108,000 |
| Florida | $20,000 – $91,000 |
| Georgia | $20,200 – $92,000 |
| Hawaii | $25,700 – $117,000 |
| Idaho | $20,700 – $94,000 |
| Illinois | $25,300 – $115,000 |
| Indiana | $22,200 – $101,000 |
| Iowa | $21,300 – $97,000 |
| Kansas | $20,900 – $95,000 |
| Kentucky | $20,500 – $93,000 |
| Louisiana | $19,800 – $90,000 |
| Maine | $21,600 – $98,000 |
| Maryland | $22,000 – $100,000 |
| Massachusetts | $25,300 – $115,000 |
| Michigan | $22,000 – $100,000 |
| Minnesota | $24,000 – $109,000 |
| Mississippi | $19,100 – $87,000 |
| Missouri | $22,400 – $102,000 |
| Montana | $21,600 – $98,000 |
| Nebraska | $20,700 – $94,000 |
| Nevada | $22,700 – $103,000 |
| New Hampshire | $21,800 – $99,000 |
| New Jersey | $25,100 – $114,000 |
| New Mexico | $20,200 – $92,000 |
| New York | $24,200 – $110,000 |
| North Carolina | $19,800 – $90,000 |
| North Dakota | $22,200 – $101,000 |
| Ohio | $22,000 – $100,000 |
| Oklahoma | $20,000 – $91,000 |
| Oregon | $24,200 – $110,000 |
| Pennsylvania | $22,200 – $101,000 |
| Rhode Island | $22,900 – $104,000 |
| South Carolina | $20,000 – $91,000 |
| South Dakota | $19,800 – $90,000 |
| Tennessee | $20,200 – $92,000 |
| Texas | $20,000 – $91,000 |
| Utah | $20,700 – $94,000 |
| Vermont | $21,300 – $97,000 |
| Virginia | $20,900 – $95,000 |
| Washington | $25,500 – $116,000 |
| West Virginia | $20,900 – $95,000 |
| Wisconsin | $22,900 – $104,000 |
| Wyoming | $21,800 – $99,000 |
These are numbers to plan with, not quotes. Each one is this guide's U.S. range, adjusted for what construction workers earn in that state. See every state cost guide or how we estimate.
Common questions
- How much does a home addition cost per square foot?
- Building out costs $80 to $350 per square foot. Building up, with a second story, costs $300 to $500 because of the structural work. Bathrooms and kitchens cost the most per square foot because of the plumbing.
- What is the cheapest type of addition?
- A bump-out or a simple ground-level bedroom with basic finishes. A sunroom can also cost less. Anything with plumbing, like a bathroom or kitchen, costs more, and so does a second story.
- Is it cheaper to build up or out?
- Building out is usually cheaper per square foot. Building up means strengthening the house you have, and you often have to move out for a while during the work. Building up does save your yard space.
- Does a home addition add value?
- It can add a lot, especially a bedroom or bathroom that fixes something your home lacks. As with any remodel, don't push your home's value past the top prices in your neighborhood.
- Do I need permits for an addition?
- Yes. Additions need building permits and inspections, and often architectural plans (detailed building drawings). Permit and design fees usually cost $2,000 to $10,000. You need them for an addition that is legal and that you can sell.
- How long does an addition take?
- A simple room addition takes 2 to 4 months. A larger addition or a second story can take 4 to 8 months, counting design and permits.
- Should I build an addition or move?
- Adding on is often cheaper, if you like where you live and the addition won't over-improve your home for the neighborhood. Buying and selling a home come with big costs of their own. Run the numbers both ways.
How we estimate: These are typical U.S. prices for materials and for hiring a pro to install them. We checked them against the 2026 sources listed below (see how we get our numbers). Your price depends on where you live, the size of the job and the materials you pick. Get two or three written bids before you choose a contractor.
Sources
We checked the prices on this page against 2026 numbers from these sources: