Home additions costs
Add living space to your home with a room extension or another addition suited to your property. Layout, foundation work, utility connections, and finish selections affect the budget. Ask your contractor to identify design, site preparation, permits, and any work on the existing house separately.
National planning benchmark. Portland-specific prices have not yet been verified.
Your price depends on project size, materials, access, and existing conditions. Confirm the scope, permits, disposal, and exclusions with your contractor.
What the project can include
- Planning and construction for additional living space.
- Foundation, framing, roofing, windows, and exterior finishes.
- Utility extensions and interior finishes suited to the new room.
Different additions have different price bases
| Addition type | National planning range |
|---|---|
| New room addition | $125–$250 / sq ft |
| Bump-out extension | $85–$200 / sq ft |
| Second-story addition | $200–$500+ / sq ft |
National planning benchmarks. Scope and local bids can differ.
What affects your price
- The addition's size, layout, and structural complexity.
- Foundation and site preparation needs.
- New bathrooms or kitchens, utility connections, and finish quality.
Before you compare bids
Clarify the room's purpose and approximate size. Ask for design, permitting, site preparation, structural work, utility connections, and finishing to be identified in the proposal.