Question: how much does it cost to build another room in your house?
Answer: The average room or house addition costs $86 to $208 per square foot, with most homeowners spending between $22,500 and $74,000. Adding a 20x20 family room costs $48,000 on average, while adding a 12x12 bedroom costs about $17,300. The cost to add a bathroom starts at $18,000.