Research
Original research from our construction-permit corpus. Every figure is measured, dated, and published with the classification precision and admission rate behind it — including the jurisdictions we exclude and why.
Reports are claims about the date they were published and are not updated in place. For current numbers, see the live status map.
One of these cities publishes nothing. The other one, we didn't read.
Philadelphia and Cincinnati look identical in our database: a description field on every permit, and a handful of distinct values across the whole corpus. One of those readings is right and the other is our fault. The check that tells them apart is fetching what the city actually publishes — and no query against our own data can do it.
Same-day permits didn't disappear. The record of them did.
130 US and Canadian jurisdictions publish a permit issue date. 22 publish enough to measure how long approval takes, and 6 survive the checks needed to believe the answer. In all six, same-day issuance has largely disappeared — and in Chicago it is datable to the month the city moved that permit class online. The change is invisible in the field itself.
Most US cities publish permit timeline data. Almost none publish it on most of their permits.
143 US jurisdictions, 23,398,188 permit filings. 100 publish both dates; 94 of the 100 we hold both for publish informative lag data; only 14 publish it on a majority of their records. Any duration computed across them is measured on an unstated subset.
Solar permitting is not moving the way the map says
Residential solar permits fell 52% in Scottsdale and 60% in Tempe while doubling in Washington DC. Three jurisdictions, two markets, 2019-2025, with measured classification precision and the coverage rate behind it.
How we measure classification precision, and what it does not cover: methodology.