Permit timelines are usually answered with a shrug, or with a number from a city web page that nobody measures against reality. This is what Seattle's own permit records actually show: the time between the date a permit was filed and the date it was issued, across 1,898 Seattle permits that carry both dates.
The short answer: the median Seattle building permit is issued 50 days after it is filed. Half are issued sooner. The middle half land between 3 and 142 days, and the type of work moves that number more than anything else — see the table below.
How long it actually takes
The timeline we measure comes directly from Seattle's official permit records, tracking the actual gap between when a permit is filed and when it's issued. This isn't a city-announced target; it’s the real-world experience of thousands of filed applications. The median figure represents the most common experience, but the range of outcomes is significant—meaning the median is the honest baseline, not the guaranteed finish line, and the spread around that median is often more important than the midpoint itself.
What the numbers say
The table below shows the median processing times across common permit types based on Seattle’s own historical data. Simple, single-trade work like deck construction or window replacements typically clears much faster than complex projects involving structural changes or new units. This speed difference exists because straightforward trades often require minimal review, while larger-scale work demands thorough evaluation of safety, zoning, and engineering compliance.
| Type of work | Median days to issue | Typical range | Permits measured |
|---|---|---|---|
| Addition | 23 | 1–77 | 1,297 |
| Demolition | 76 | 21–152 | 142 |
| Deck / patio | 4 | 0–54 | 130 |
| ADU / accessory unit | 197 | 126–326 | 125 |
| Foundation / seismic | 23 | 3–59 | 82 |
| Windows | 3 | 1–5 | 63 |
| Bathroom remodel | 4 | 0–11 | 30 |
| Kitchen remodel | 2 | 0–9 | 28 |
What actually drives your timeline
- A complete application with all required documents avoids the initial hold that delays processing.
- Permits requiring detailed plan review by city staff inherently take longer than simple over-the-counter permits.
- Each round of revisions requested by the city adds significant time to the process.
- Unplanned changes to the original scope after filing can trigger new reviews and delays.
- Seasonal demand fluctuations and existing backlogs at the city office directly impact current processing speed.
How to use this
Compare your project type to the issued permits in the table to set realistic expectations. If your work aligns with a category known for quick issuance, a longer wait may indicate a specific issue with your application rather than a general city slowdown. Conversely, if your project matches a slower category, use the table to understand the typical range and proactively check in if your application exceeds the median timeline for that category.
Check your own project
Look up what comparable permits actually cost and how long they took with the free permit benchmark check — pick Seattle, your type of work, and your budget.
- Seattle building permits: search and history — recent filings with addresses, types, and valuations.
- Look up a specific address — see what has been filed at a property.
- Weekly Seattle permit digest — the biggest projects filed each week.
Timelines are measured from The Permit Sheet's copy of Seattle's official permit records and reflect permits that were actually issued. They are a description of what happened, not a promise about your application.