Adding a Bedroom or Office? How Much Does a Room Addition Cost?
You love your space, but honestly, you could use a little more space. If you add a home office, an ensuite, or just a few more feet to your kitchen, you could transform your house into a forever home. So, around how much would a room addition cost? According to HomeAdvisor, homeowners spent on average $21,960 to $82,344 to add onto their homes. That’s a helpful start, but that’s a pretty big range.
According to Harvard University’s Joint Center for Housing Studies, “Homeowner expenditures for improvements and repairs are expected to trend up through the first half of 2025.” To zero in on the most current average costs and how much of the cost you can hope to recoup when you sell, we spoke with several experts:
Allison Harris, a top real estate agent with Keller Williams in Savannah, Georgia, who has over 545 real estate transactions under her belt
Jerome Leyba, a top real estate agent for Keller Williams in Santa Fe, New Mexico, who specializes in new construction
Mark Poulton, a production manager who has over 36 years of experience in building and home remodeling
Jim Pitzen, a licensed architect and sales and design director at COR Improvements
We break down room additions by the project to help you craft a custom estimate, and break down important questions to ask a potential contractor.
Room addition cost overview
Depending on the function of the room and the type of addition (i.e., bathroom or home office, bump out or full addition), the size and cost of your addition will vary. Below is a list of the most common room additions and their costs. We’ll take a closer look at each project in the next section.
Project
Room Addition Cost
Home office
$2,000 – $22,000
Bump out
$5,000 – $35,000
Dormer
$6,000 – $25,000
Balcony
$1,000 – $8,000
Laundry room
$1,300 – $15,000
Mudroom
$6,500 – $18,000
Porch
$4,000 – $90,000
Sunroom
$6,500 – $124,000
Cantilever
$15,000 – $25,000
Garage
$19,600 – $28,200
Bathroom
$5,000 – $75,000
Kitchen
$35,000 – $95,000
Primary bedroom suite
$37,500 – $117,000
In-law suite
$25,000 – $265,000
Home theater
$10,000 – $60,000
Methodology
Angi analyzes homeowner surveys to determine average spending of completed home improvement projects.
HomeAdvisor gathers millions of real project costs from real homeowners in more than 10,000 U.S. cities and towns.
Fixr reviews cost information with experts in different fields of home improvement or design. They also check specialized publications, cost studies, and U.S. government reports.
HomeGuide tracks millions of cost estimates for home improvement and repair projects to find their true cost.
Remodeling Calculator uses prices that are an aggregate of input from hundreds of pros across the U.S., as well as rigorous pricing research that is regularly updated.
