Building permit data, mapped

Permit data sources by city

Most permit data in the US is public and free — the hard part is that every jurisdiction publishes it differently. Big cities run modern open-data portals (many on Socrata or ArcGIS) with daily updates and APIs; smaller ones publish CSVs or nothing at all. Here's where the major markets stand.

What permits do — and don't — tell you

A permit is a dated commitment to real work: it names an address, a type of work, a filing date, and usually an applicant. That's a genuine buying signal for the trades and suppliers who serve a project. What a permit doesn't include is the one thing you need to win the work: the decision-maker at the account and a verified way to reach them. Closing that gap — matching the filing to the owner, finding the person who signs, and verifying their contact — is the enrichment step.

DIY vs done-for-you

You can absolutely run this yourself: pull the portal, filter by type and recency, and cross-reference ownership. It works, and for a single market it's a reasonable afternoon. The reason to hand it off is scale and freshness — monitoring every source daily, joining permits to violations and registrations, and enriching contacts is a pipeline, not a spreadsheet. That pipeline is the product.