Keyser Construction

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Portland Metro · Since 1998

Finished basements that don't feel like basements.

The cheapest square footage you'll ever add. We've been finishing Portland-area basements for decades, with the moisture management, radon mitigation, and egress work that separates a real living space from a damp afterthought.

The room that pays for itself.

An unfinished basement adds a family room, guest suite, home office, gym, in-law suite, or rental income, without changing your home's footprint or eating into your yard. The catch in our region is moisture: finishing over a damp basement is how you turn it into a mold problem. We check that first.

Same crew through the whole job: framing, electrical, plumbing, HVAC tie-in, drywall, tile, flooring, finish work.

What we include in a Keyser basement finish

  • Framing, insulation, drywall, paint to current code (fire-blocking, vapor)
  • Egress windows where bedrooms are added (we coordinate the excavation and well install)
  • Plumbing for bathrooms, wet bars, kitchenettes, including under-slab drains
  • Electrical: outlets, lighting, dedicated circuits, sub-panel install when load requires
  • HVAC tie-in or mini-split heat pumps (often the best basement solution)
  • Flooring suited to below-grade: LVP, engineered with vapor protection, polished concrete
  • Built-ins, custom storage, media walls, wet bars, full kitchens
  • Radon testing and mitigation when warranted

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

Moisture comes first

Portland basements are usually dry, but not always. Before we frame anything we check foundation cracks and seepage, exterior grading, gutter and downspout extensions, sump and drain function, and the humidity baseline.

When we find problems we address them with proper drainage, waterproofing, sump installation, or interior membrane systems before any new framing goes up. Finishing over a wet basement isn't a corner we cut.

Radon: the conversation Portland homeowners often skip. Parts of the Portland metro are in EPA Zone 1 and 2 for radon. Finishing a basement that's going to be used as living space is the right time to test and add mitigation. A few hundred to a few thousand during finish-out, versus much more done later.

How a Keyser basement finish runs

Moisture audit first. Then design and build.

01

Moisture and code audit

We walk the basement, check for seepage and humidity, look at exterior grading, confirm ceiling height for finished space, and identify what's going to need egress work. Free, no obligation.

02

Design, selections, estimate

Layout for how you'll use the space, finishes, mechanicals. Line-item written estimate with permit fees, radon mitigation, and egress work itemized. We pull the permits.

03

Build, inspect, walkthrough

Egress window cuts, framing, electrical, plumbing, HVAC, drywall, finish flooring, paint, trim. Inspections at each stage. Final walkthrough, punch list, and warranty paperwork at close.

Ready to add real square footage?

Tell us what you want the basement to be. We come out, walk the space, and follow up with a written estimate within a week.

Code, permits, and what the inspector looks at

Finished basements require permits and inspections in every Portland-area jurisdiction. The items inspectors look hardest at:

  • Egress: any bedroom requires a code-compliant egress window or door
  • Ceiling height: minimum is generally 7'0" with some exceptions for beams
  • Smoke and CO detection integrated with the main house
  • Stair compliance: tread depth, riser height, guardrail
  • Fire blocking and draft stops in concealed spaces
  • Insulation values matched to Oregon's energy code

We handle all of this in the permit set and during inspections.

Typical Portland-area basement pricing

Mid-2020s Portland market. Real ranges. Egress cuts and moisture work, when needed, are itemized separately.

$40K+
Simple finish (one open space, no bath)
$80K+
Mid-range (living + half bath + bedroom, 800-1,200 sq ft)
$120K+
Full guest suite (bedroom, full bath, living)
$150K+
In-law or ADU-grade (full kitchen, bath, entry)

Basement finish FAQs

How long does a basement finish take?
An average 800 to 1,200 sq ft basement finish runs 8 to 16 weeks of active construction. Plan another 4 to 8 weeks of front-end time for design, permits, and waterproofing or excavation work if needed. Egress window cuts add 1 to 2 weeks on the front end.
Will the finished basement add to my home's value?
In the Portland market, a properly permitted basement finish typically returns 60 to 80 percent of its cost at resale, sometimes more if it adds bedroom and bath count. Permitted is the key word: appraisers and inspectors discount or disqualify unpermitted finished basement space.
Will it feel like a basement, or like real living space?
Depends on the basement and the design. We can make a basement feel like upper-floor space with the right lighting plan, ceiling-height management, egress window cuts that bring in real daylight, and finish choices that don't read as "basement materials." Some basements are easier to elevate than others. We'll be honest about what's achievable in yours.
Do I need to test for radon?
Yes, for any basement going to living-space use. Tests run $50 to $200, take a few days, and tell you whether you need mitigation. Mitigation is cheap during build, expensive later.
What about turning the basement into an ADU or in-law suite?
Both are common. See our ADU page for the standalone-permit version, and our mother-in-law suite page for the attached version. Different zoning, different fees.
How do we get started?
Send a note or call (503) 997-5895. We'll come out, walk the basement, and follow up with scope and budget within a week.

Recent Keyser Interior Projects

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.

More interior work from our archive

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Interiors Additions: rowzee 1
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Interiors Additions: img 6962
Interiors Additions: img 3532
Interiors Additions: img 0612
Interiors Additions: int jbi 06 16
Interiors Additions: beard bed wide angle

Let's plan your basement.

Free in-home walk-through with moisture audit. Written estimate with line-item detail. One crew start to finish.