Keyser Construction

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Portland Metro · Since 1998

Additions that don't read as additions.

A primary suite, a growing-family bedroom, a great-room bump-out, a second story. Done right, the addition disappears as an addition and just becomes part of the house. Done wrong, the seams are visible forever.

When the inside changes alone won't get you there.

Additions make sense when you love the lot and neighborhood, when moving costs more than building (often the case in West Linn, Lake Oswego, Beaverton, NE Portland), and when you're staying long enough for the addition to pay back through use, not just resale.

If you want a separate dwelling on the same lot, see our ADU page. For a family member living in an attached suite, see mother-in-law suites.

Real credentials. Verifiable.

Every license and rating below is independently verifiable.

Since 1998
Family-owned, owner on every project
CCB #121142
Oregon licensed contractor
A+
BBB rated since 2007
EPA
Lead-Safe Renovator Certified

Additions we build

  • Primary-suite additions (bedroom + bath + walk-in closet), usually 350 to 700 sq ft
  • Family-room and great-room bump-outs that open the back of the house
  • Second-story additions over existing single-story homes
  • Bedroom additions for growing families, often paired with another bath
  • Four-season sunrooms engineered and insulated for year-round Portland use
  • Garage additions and garage-to-living-space conversions
  • Kitchen expansions: pushing the kitchen out into a back or side addition
  • Mudroom and entry additions: small but useful daily-logistics wins

Making the addition read as part of the house

A common reason additions look like additions instead of like the house grew naturally:

  • Matched exterior materials: siding profile, trim, paint, roof, gutters
  • Matched window style: same manufacturer, same grille pattern, same proportions
  • Matched roofline: same pitch, integrated rather than tacked-on
  • Matched interior finish: floor that flows from old to new, base and casing profiles, paint color carried through
  • Hidden structural transitions: no visible step in ceiling height, no patch lines

Done right, the addition disappears as an addition. Done wrong, the home's value reflects it.

How a Keyser addition runs

Design, structural, permit, build. Months on the front end pay back during construction.

01

Consultation & feasibility

We walk the house and property, talk through what you want to add and why, and check setbacks, lot coverage, tree preservation, and structural realities. Free, no obligation.

02

Design, engineering, estimate

In-house drafting for simpler additions or coordination with an architect for larger projects. Structural engineering for second-story additions, removed walls, or addition tie-ins. Line-item written estimate once design is mature.

03

Site work, build, inspect

Excavation, footings, foundation, framing, mechanicals, siding matched, roof tied into existing, finishes. Final inspections and walkthrough at close-out.

Ready to add the space you actually need?

Tell us what you want to add and where on the house. We come out, walk it with you, and follow up with a written estimate.

Portland-area addition considerations

  • Lot coverage and setbacks vary by jurisdiction. Portland, Beaverton, Lake Oswego all have different rules
  • SDC (System Development Charge) fees can be significant for additions that add bedrooms or living space
  • Sewer and water tie-ins may need updating for additional fixtures
  • Stormwater requirements have tightened in many Portland-area jurisdictions
  • Design review applies in certain neighborhoods and historic districts
  • Tree preservation rules can affect where a footprint can go

We check all of this before designing, not after.

Typical Portland-area addition pricing

Mid-2020s market. Permitting in some Portland-area jurisdictions adds 2 to 4 months on the front end of any of these.

$80K+
Single-room (bedroom, sunroom, modest bump-out)
$180K+
Primary suite (bedroom + bath + closet, 350-600 sq ft)
$200K+
Great-room or kitchen-expanding bump-out
$350K+
Second-story or large multi-room addition

Home addition FAQs

How long does a home addition take?
Single-room addition: 3 to 5 months of active build. Primary suite addition: 5 to 7 months. Second-story: 6 to 9 months. Large multi-room: 6 to 10 months. Add 2 to 4 months of permit time on the front end.
Can we stay in the house during the build?
Most additions can be built while you stay in the house. The work is mostly outside the existing footprint until the tie-in phase, when we open the wall between old and new. We coordinate that opening with temporary weather sealing. Second-story additions are the exception: raising or removing a roof usually requires a temporary move or significant disruption upstairs.
Will an addition pay for itself at resale?
Sometimes. In the Portland market, well-designed additions that add bedroom and bath count typically recover 60 to 80 percent of cost at resale, sometimes more. Pure great-room bump-outs return less but produce more daily-life value. We'll be honest about what to expect.
Can we add a second story?
Usually yes, but the existing first-floor structure has to support the load, and there are practical considerations (temporary roof during construction, stair location, integrating new HVAC and electrical). Worth a feasibility consultation before committing.
What about SDC fees?
System Development Charges can run $10K to $40K+ on bedroom-adding additions in some Portland-area jurisdictions. We pull them into the estimate up front so the number you sign for is the real number.
How do we get started?
Send a note or call (503) 997-5895. We'll come out, walk the house and yard, and follow up with scope and budget direction within a week.

Recent Keyser Additions & Interiors

Our Promise

Every project backed by our written warranty.

Workmanship warranty included in every contract, in writing. If something we built isn't right, we come back and make it right.

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Let's plan your addition.

Free in-home walk-through with feasibility check. Written estimate with line-item detail.