Home additions costs
A ground-level room addition and a second story require different structures and trade work. Define the room use and connection to the existing house.
Planning benchmarks: These ranges are national unless a row explicitly says Oregon or Washington statewide. Portland Metro prices have not been independently verified. Actual bids depend on the property and specified work.
Installation and project cost
Start with the project scope below. Installed totals include the work described in that row; repair, replacement, and construction scenarios are separate alternatives. Confirm removal, preparation, permits, delivery, and finish work in the written bid. Do not add overlapping totals together.
| Project or option | Planning range | Basis and scope |
|---|---|---|
| Home addition cost | $125 – $250 | per sq ft; home addition |
| Home addition cost | $50,000 – $100,000 | 20-by-20-foot addition |
| Cost to add a second story | $200 – $500 | per sq ft |
What the project can include
- Foundation and framing
- Roof and exterior
- Utilities and interior finishes
What changes the price
- Addition type
- Structural changes
- Finish level and size
Ask for separate allowances for preparation, removal, delivery, materials, labor, and finish restoration where they apply.
Before you request local bids
Share measurements, photos, the property location, existing conditions, desired materials, and your target schedule. Ask each professional to quote the same written scope, list exclusions and allowances, and identify any design, permits, utility work, disposal, or restoration that needs separate pricing.
Use the contact form to describe your project and request follow-up for Portland Metro.