Home Addition Contractor in Portland, OR
Typical range: $60,000 – $250,000 Final price depends on scope — your free estimate is itemized in writing.
Estimate your project →Room Additions and Home Additions
A room addition is a different job from a remodel, and the difference is everything underneath. New foundation, new framing, a roof that has to tie into the existing one without leaking in a Portland winter, and siding and trim that have to read as part of the house rather than something bolted on.
That last part is where most additions give themselves away. Matching a 1950s roofline, or a lap siding that has not been manufactured in thirty years, is a detail problem, and we would rather solve it in the drawings than explain it afterwards.
The additions people ask us for most: a bedroom with its own bathroom, a primary suite, a family room off the back, an office with a door that closes. We recently finished a Portland addition that combined a bedroom, a private bath and a laundry room in one build — one foundation, one roof tie-in, three rooms gained.
Full scope in house: foundation, framing, roofing, siding, windows, insulation, drywall and finish. Electrical and plumbing through licensed subcontractors. Permits pulled and inspections scheduled by us, not by you.
Second-Story Additions
Going up instead of out is the answer when the lot is full — a small city lot, a steep slope, mature trees you are not allowed to remove, or setbacks that leave nowhere to build.
It is also the most demanding addition there is. The existing foundation and walls have to carry a floor they were never designed for, which usually means an engineer, new footings or posts, and sometimes work in the basement before anything happens upstairs. The roof comes off. You are generally out of the house while it does.
What that buys you is the only kind of addition that does not cost you yard. On a tight Portland lot it is often the only legal way to add real square footage at all.
We will tell you early whether the house will take it. Some will, some will not, and the structural answer comes before the design, not after you have paid for drawings.
What Your Lot Allows, Before You Pay for a Design
Three things decide what is possible before anyone draws anything, and all three are public record.
Setbacks. How close to each property line you are allowed to build. They vary by zone, and they are the most common reason a planned addition shrinks.
Lot coverage. The share of your lot that structures are allowed to occupy. Garages, covered porches and sheds usually count. Plenty of Portland lots are already near the cap.
Height and stories. What the zone permits, plus any overlay — historic districts, environmental zones and tree protections all add requirements and time.
We check these for your address at the first visit, free, before you have spent anything. Sometimes the answer is that the addition you pictured will not fit but a smaller one will. Sometimes it is that your attic or basement gets you the same room for a third of the price. We would rather tell you that on day one than take a deposit for a design that was never going to be permitted.
How We Build an Addition
Feasibility visit. We walk the site, measure, and check setbacks, lot coverage and height for your address. Free, no deposit. You get a straight answer about what will fit.
Design and engineering. Drawings, and a structural engineer where the work needs one, which on a second storey it always does.
Permit. We file with the city or county your address falls under and manage the review. Expect roughly four to eight weeks for a straightforward addition and longer where a land use review or a historic district is involved.
Build. Foundation, framing, roof tie-in, weatherproofing, then the inside. We close the house in before wet weather can reach anything that matters, which in Portland dictates the schedule more than people expect.
Inspections and close-out. We schedule them, we meet them, and you get the signed permit at the end. An unpermitted addition is worth nothing at appraisal and becomes the buyer's problem when you sell.
Through all of it, one point of contact and a written line-item estimate you were given before the work started.
What a Portland Addition Costs
Most of the additions we build land between $60,000 and $250,000. Our most recent Portland addition — a bedroom with a private bathroom and a laundry room, one foundation, one roof tie-in — came in at $240,000.
By type: a room addition runs $200 to $350 per square foot, so a 200 to 400 square foot addition sits between $40,000 and $140,000. A bump-out is $200 to $400 per square foot. A second storey is its own category at $250 to $400 and up, and a full one over a 1,200 square foot house reaches $300,000 to $480,000.
What moves those numbers most: how far plumbing has to travel, whether the roofline is simple or complicated, what the foundation finds when it is dug, and whether the house needs structural work to carry what you are adding.
Additions typically return 50 to 70 percent of their cost at resale. The rest of the value is the years you live in the room.
You get a written line-item estimate before anything begins. No deposit to get a number.
Frequently Asked Questions
Common questions about Home Additions in Portland, Oregon.
Get Your Free Home Additions Estimate
Licensed, insured and bonded contractor serving Portland, Beaverton, Gresham, Lake Oswego, Tigard and surrounding Oregon communities.
