Basement Finishing cost in Seattle, WA (2026)
For a typical 800 sq ft basement finishing in the Seattle metro, mid-range typically runs $22,370. Labor here averages 25% above national trade wages, with materials at each tier's quality level and contractor overhead applied the way contractors actually bill.
Standard-tier breakdown, line by line
| Line item | Category | Typical cost |
|---|---|---|
| Flooring material | Material | $2,800 |
| Egress window (if required) | Material | $2,400 |
| Wall framing | Labor | $2,244 |
| Framing lumber and hardware | Material | $2,000 |
| Electrical rough-in and finish | Labor | $1,823 |
| Drywall installation and finishing | Labor | $1,630 |
| Electrical supplies and fixtures | Material | $1,600 |
| Drywall | Material | $1,440 |
| Flooring installation | Labor | $1,290 |
| Insulation | Material | $1,200 |
| Trim and baseboards | Material | $800 |
| Painting | Labor | $629 |
| Insulation installation | Labor | $625 |
| Trim installation | Labor | $561 |
| Plumbing (if adding bathroom) | Labor | $527 |
| Paint and primer | Material | $400 |
| Misc supplies and fasteners | Supplies | $240 |
| Debris removal | Disposal | $160 |
| Total (incl. overhead) | $22,370 |
Seattle trade wages behind this estimate
| Trade | SOC | Median /hr | vs. national |
|---|---|---|---|
| Carpenters | 47-2031 | $33.40/hr | +25% |
| Electricians | 47-2111 | $40.70/hr | +29% |
| Drywall and Ceiling Tile Installers | 47-2081 | $29.10/hr | +18% |
| Floor Layers, Except Carpet, Wood, and Hard Tiles | 47-2042 | $28.80/hr | +30% |
| Painters, Construction and Maintenance | 47-2141 | $28.10/hr | +24% |
| Insulation Workers, Floor, Ceiling, and Wall | 47-2131 | $27.90/hr | +23% |
| Plumbers, Pipefitters, and Steamfitters | 47-2152 | $39.20/hr | +28% |
This page shows the typical range. Your project isn't typical — build the line-item estimate for your exact scope in the free iOS app.
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Washington permit guide →Basement Finishings — what homeowners ask
Finishing a basement costs $25-$60 per square foot. A basic finish with drywall and flooring costs $25-$35/sqft, a mid-range finish with bathroom and kitchenette runs $35-$50/sqft, and a high-end finish with wet bar and home theater can exceed $60/sqft.
Finishing a basement typically recoups 60-70% of costs in home value and adds usable living space. It is one of the most cost-effective ways to add square footage to your home without building an addition.
A basement finishing project typically takes 4-8 weeks. Simple conversions with minimal plumbing can be done in 3-4 weeks, while full buildouts with bathroom, kitchen, and custom finishes may take 8-12 weeks.