How long a Seattle home takes to build, September 2026
Residential building work finished in September 2026 had taken a median of 9.5 months from the day its permit was issued, across 391 completed permits. A year earlier the median was 9.7 months. Over the series it has run between 5.3 months (September 2012) and 17.9 (March 2017).
This is the half of the housing debate that permit counts miss. How many units a city permits is the number everyone argues about; how long those units then take to exist is what decides when anyone lives in them. A city can permit its way to a record year and add nothing to the housing stock for two more.
Read the dating carefully, because it is the one thing that can mislead here. Each month counts permits that finished in it, not permits issued in it. That is the only computable choice — the permits taking longest have not finished yet, so dating by issue month would report only the fast ones and understate the lag by construction — but it means a month is characterised by whatever happened to complete in it. Completion is a records event as well as a building one, so a batch of old permits closed in an administrative clean-up lands as one slow month. Median rather than mean, so a single decade-long project does not move the line, and months with fewer than 20 completions are dropped.
Source: City of Seattle SDCI, Built Environment Permits, via data.seattle.gov (Socrata 76t5-zqzr). Median months from issue to completion for residential permits, dated by month of completion; months with fewer than 20 completions are dropped. Auto-generated each build.