Cross-jurisdiction comparison
ADU / Guest House costs 3.4× more in Seattle than in Montgomery County
6,021 permits across 10 jurisdictions. Each bar is the median value declared on the filing.
Reading the spread
Across 10 jurisdictions the middle one files a median of $123,470, and 4 of them land within a quarter of that. The gap in the headline is between Seattle and Montgomery County — a difference between cities, not a range to expect inside one.
Within a single city the spread is wider still. Montgomery County runs from $25,000 at the tenth percentile to $352,000 at the ninetieth, 14.1× end to end, while Raleigh is the tightest at 3.0×. That is the number worth carrying into a conversation with a contractor: a quote outside your own city's range is worth asking about, and a quote outside another city's tells you nothing.
8 of these 10 jurisdictions cleared 60 permits, which is the bar this site sets before a city may hold either end of a comparison. The rest are shown because their own page is worth reading, not because they are precise enough to headline.
Full numbers
| City | 10% | Median | 90% | Permits |
|---|---|---|---|---|
| Seattle, WA | $119,986 | $219,202 | $640,153 | 1,195 |
| Everett, WA | $33,000 | $175,630 | $450,000 | 97 |
| Corona, CA | $63,667 | $166,105 | $201,087 | 88 |
| San Francisco, CA | $35,994 | $165,000 | $309,999 | 167 |
| Sacramento, CA | $46,315 | $123,470 | $211,170 | 38 |
| Raleigh, NC | $75,333 | $113,354 | $226,053 | 69 |
| Los Angeles, CA | $30,000 | $100,000 | $250,000 | 4,156 |
| Chicago, IL | $35,000 | $94,100 | $340,000 | 53 |
| New York, NY | $33,356 | $90,000 | $421,152 | 97 |
| Montgomery County, MD | $25,000 | $65,000 | $352,000 | 61 |
Declared permit values, last 24 months. Updated 2026-09-24. Methodology.