Room Addition Cost
Mary Stepien

At  $128 per square foot , a 10×20 bedroom addition costs  $25,600  on average, while a 20×20 family room ranges from  $51,200 . When adding a bathroom that requires plumbing, expect to spend from  $18,000 to $47,000 .

There are many ways to increase your square footage. You can build up by adding a second floor, or you can build out and add a room by adding a section of house that attaches through an opening in an outside wall. You can also convert one kind of room to another kind of room better suited to meet your needs. You can build a detached garage or workshop. All options qualify as a house addition.

When considering a significant room addition, be sure to consult with an architect to draft the design and style you’re looking for. Next, hire a structural engineer to make sure the addition plans are sound before construction. Finally, hire a general contractor who will coordinate all the development and building in the correct order.

Adding A Room To A House

It’s impossible to figure the exact cost of adding a room to a house until you know the size of the room and every aspect of what’s built into it. The cost of labor in the area where you live will also impact the price. The following examples reflect the general cost of the project.

Garage remodeling services
By Mary Stepien October 16, 2025
Upgrade your garage with HRC Inc’s expert remodeling and renovation services — functional designs, durable finishes, and seamless transformations.
Expert Renovation Services
By Mary Stepien October 15, 2025
Transform your home in The Villages with HRC Inc’s expert renovation services — kitchen, bath, additions, and full remodels with quality craftsmanship and reliable support.