The cost to add a room to a house in 2025 generally ranges from about $21,000 to $73,000 on average, with some projects costing as low as $8,000 and others exceeding $130,000 depending on many factors such as the type of room, size, materials, labor, and location. The average cost per square foot tends to be between $150 and $300. Here are some specifics by room type and size:
Average Cost by Room Type
- Bathroom: $10,000 – $20,000
- Bedroom: $16,000 – $26,000
- Family room: $26,000 – $41,000
- Kitchen: $21,000 – $51,000
- Primary suite (master bedroom with amenities): $46,000 – $136,000
- Sunroom: $16,000 – $106,000
Average Cost per Square Foot by Room Type
- Bathroom: $180 – $230/sq ft
- Bedroom: $130 – $180/sq ft
- Family room: $130 – $180/sq ft
- Kitchen: $250 – $300/sq ft
- Primary suite: $180 – $250/sq ft
- Sunroom: $150 – $400/sq ft
Cost Estimates by Room Size
- 10x10 room (100 sq ft): $13,000 – $26,000
- 12x12 room (144 sq ft): $19,000 – $37,000
- 20x20 room (400 sq ft): $51,000 – $101,000
The final cost depends heavily on whether the addition requires new plumbing, electrical work, the quality of finishes, contractor labor rates, and the complexity of the construction project. Geographic location also plays a significant role in pricing. In summary, adding a new room could cost anywhere roughly from $13,000 for a smaller basic room up to over $100,000 for larger or more complex additions like master suites or kitchens. Planning for an average around $49,000 is reasonable for typical room additions in 2025.
