Where to Get Building Permit Data (and How to Use It)

What building permit data is

Building permit data is the structured record of construction approvals issued by a local authority having jurisdiction — usually a city or county building or development-services department. Each record represents a building permit: an official authorization to perform construction work that meets adopted building, zoning, and trade codes. A typical permit record includes the property address, permit type, a description of the work, the status, key dates, and often the estimated project valuation and owner or contractor information.

Because permits are issued before and during construction, the data is a leading indicator rather than a lagging one. A new permit filing tells you a project is starting, not that it already finished. That timing is exactly what makes the data valuable: it surfaces demand at the point where outreach, financing, and supply decisions still matter. The catch is that permit records are generally public but live in each jurisdiction's own system, which is why getting comprehensive data takes work.

Public and open-data sources

There are a few broad ways to access building permit data. The most direct is each jurisdiction's own permit-search portal, where you can look up records one at a time. For bulk access, many cities and counties now publish permit datasets on municipal open-data platforms. Two of the most common are Socrata (used by many city open-data sites) and Esri ArcGIS (which hosts geographic feature services that include the permit's location). Some agencies also publish downloadable CSV exports, and where no portal exists at all you can often obtain records through a public-records or FOIA-style request.

These sources are factual and public, but they vary enormously in quality and structure. One city might expose a clean dataset with a dedicated ADU subtype and a consistent ZIP field; another might bury the relevant signal inside free-text work descriptions and omit ZIP codes entirely. Field names, date formats, status vocabularies, and update frequencies all differ from portal to portal, and some feeds order records in ways that make it hard to tell which ones are newest. A field that exists in one city's dataset simply won't exist in the next, so a query that works perfectly for one market breaks for another.

The data is out there — but assembling it across many markets means reconciling all of those inconsistencies into a single comparable view, which is the core difficulty in working with permit data at scale. That reconciliation work is the difference between a pile of city exports and a dataset you can actually query and trust.

What good permit data looks like

Raw access to a portal is not the same as good data. A few qualities separate data you can act on from a pile you have to clean first. Freshness comes first: permit signals decay quickly, so data that surfaces within hours of posting is far more useful than data that's weeks old. Igni, for example, ingests from official open-data portals with sub-24-hour freshness.

Classification matters just as much. Good permit data tells you what kind of project a record represents rather than leaving you to read every description. A typed ADU classification — detached, attached, junior ADU, conversion, or unknown — turns a messy free-text field into a filterable category. Completeness rounds it out: recovered ZIP codes for records that lack them, a normalized valuation for project size, consistent statuses and dates, and California SB-9 and SB-10 flags where they apply. When those pieces are in place, you can filter and compare permit activity across many cities as if it came from one source — which is the whole point.

How builders and lenders use permit data

Different users extract different value from the same dataset. Builders, contractors, and suppliers use permit data as a demand map: knowing which neighborhoods are seeing new ADUs, additions, or remodels lets them focus marketing, staffing, and bids where the work actually is, and reach owners early in the project. For specialized trades and ADU builders, a typed feed means they can target precisely the project types they take on instead of reading every record by hand. A roofing supplier, an HVAC contractor, and an ADU designer can all pull very different slices from the same underlying data.

Lenders, investors, and real-estate professionals read the same data as a market signal. A cluster of new residential permits points to where construction lending, renovation financing, or investment activity is heading before it shows up in slower indicators like sales or appraisals. Tracking permit valuation and volume over time across neighborhoods can reveal momentum that isn't yet visible elsewhere, which is useful for underwriting, sizing a market, or deciding where to expand.

Because the underlying records are public, the data is verifiable and broad — but speed and good filtering are what create the advantage, since you're generally not the only one who can access it. The teams that win are the ones who can act on fresh, well-classified data faster than competitors working from stale exports. If you'd like to discuss how Igni's normalized feed fits a specific use case, get in touch and tell us the markets and project types you focus on.

Start with the free permit-lookup tool

The fastest way to see what building permit data looks like in your market is to try it directly. Igni offers a free permit lookup where you can search recent permit activity and see how records surface with addresses, types, and ADU classification applied — no commitment required.

From there, you can explore the breadth of coverage on our coverage hub, or drill into individual markets like Los Angeles permit data, Seattle permit data, and Austin permit data to check whether the cities you care about are live. Igni is contact-driven during its pilot, so when you're ready for filtered, ongoing access across your markets, reach out and we'll walk through coverage and fit. As always, this is general information about working with public permit data, not legal advice.

Frequently asked questions