1 Choice Construction
RESIDENTIAL · BASEMENTS

Turning an unfinished basement into real, legal living space.

A basement is the cheapest square footage you'll ever add — if it's done right. Egress, moisture, and ceiling height are what separate finished living space from a damp room nobody uses.

Egress & moistureCode-compliant finishAdded living space
Turning an unfinished basement into real, legal living space. — illustration showing the design resolving into a finished build
Concept illustration

Is this you?

You've got unfinished or half-finished square footage downstairs and you want it to count — a family room, a guest suite, an office, or a separate living area. You want it dry, warm, code-compliant, and actually pleasant to be in.

This fits if you want to:

What’s included — and what’s not

IncludedNot included
Layout, egress, moisture, and finish designExcavation to lower the floor (priced separately if needed)
Framing, insulation, drywall, flooring, lightingFurniture and décor
Egress window/well where a bedroom is addedFoundation repair (priced separately if found)
Permits, inspections, and correctionsDetached or exterior work outside scope

How it works

  1. Consultation — we check moisture, ceiling height, egress, and what the space can become.
  2. Design + selections — layout and finishes that fit the constraints of the space.
  3. Permits — pulled for the finish, plus egress and any bedroom requirements.
  4. Build — moisture control, framing, systems, insulation, and finishes.
  5. Walkthrough — punch list, final inspection, clean hand-back.
Dry first, finished second. Finishing over a moisture problem just hides it until it ruins the drywall. We diagnose and handle water and ventilation before anything gets covered, so the space stays dry for good.

Seattle & King County notes

A finished basement — especially one with a bedroom — needs a permit and code-compliant egress in Seattle and across King County. Ceiling-height minimums and egress-window sizing are non-negotiable; we design to them from the start rather than fail an inspection.

Common questions

Yes — code requires a compliant egress window and well for any below-grade bedroom in Seattle and King County. We size and install it as part of the job.

Start with a conversation

Tell us what you want to build.

Walk us through the space and what you have in mind. We'll talk through scope, what your city allows, and how we'd approach it.

Get a consultationSee our work