Home / Remodeling Costs in Seattle, Washington / Deck Build

Deck Build Cost in Seattle, Washington

The median declared cost of a deck build in Seattle, Washington is $22,193, based on 404 residential building permits issued in the last 24 months.

Updated November 2026 · next refresh December 2026 · computed from permits issued through November 2026.

How to read this number

These are declared permit values — the job value the applicant reported to the City of Seattle when the permit was filed. Declared values are a real-world sample of what these projects get filed at, but they are not final invoices: applicants have no reason to inflate them, and final costs often run higher once the work is done. Use the median as a planning anchor and the range to see how far real projects spread.

One more caveat: a permit value covers the whole permitted job. When a deck build is filed together with other work, the single declared figure covers all of it — one reason the top of the range runs high.

Building the deck yourself, the permit value is only part of the budget. The ground underneath it matters too: the gravel calculator sizes the base and drainage layer under the frame, and the square footage calculator gives you the deck's true footprint — the number the board count and the footing layout both start from.

How the costs spread

Half of all permits in the sample declared between $10,935 and $50,000. The full spread is wider: the cheapest 10% declared under $6,815, and the most expensive 10% declared over $93,800.

How to read this: half of all deck permits declared less than the median; 90% declared less than the right-hand figure.

Median cost by ZIP code

The same project, priced by neighborhood. ZIP medians use the same 24-month sample as the headline figure; a ZIP is listed only when at least 30 of its permits are in the sample.

How this project gets permitted in Seattle

Seattle permit descriptions name the review path each job actually took. Of the 378 permits in this sample whose descriptions name it, 62% went through full plan review (143 STFI vs 235 full plan review). STFI is the city's faster track for work that does not need a full plan check; structural work goes through plan review.

The permit itself is a small line item. SDCI charges by declared value (Development Fee Index, Seattle Municipal Code 22.900D.010, Tables D-1 and D-2): at this project's median declared value of $22,193, the building permit and plan review on the full plan review path come to about $1,401, including the 5% technology fee and the $6.50 state building-code fee. Across the middle half of declared values ($10,935–$50,000), the same fees run about $1,025–$2,309. Trade permits (electrical, plumbing, mechanical) are charged separately.

Trend

Median declared cost was $28,000 in 2024 (18 permits) and $23,097 in 2026 (201 permits) — down about 18% across the two years.

Recent deck build permits in Seattle

Anonymized examples from the sample — work description and declared value as filed, no addresses or names.

Methodology

We pull every issued residential building permit the City of Seattle publishes through its open-data portal (Socrata), keep permits from the last 24 months with a declared value above zero, and classify each one by the project its description names. Records above $2,000,000 and statistical outliers (outside 1.5× the interquartile range) are excluded before the median is computed. Every classifier rule set is spot-checked by hand against 20 sampled permits before a project type is published. This page is refreshed monthly from the permit archive.

Frequently asked questions

Plan the work

More Seattle remodeling costs

About the author

Harrison Alley is a web publisher and data enthusiast based in Dallas, Texas. He built Urbarama’s remodeling calculators and maintains them.

Harrison Alley on LinkedIn