How to Find Off-Market New Constructions

Using open building permits data

Wherever you look, housing market is crazy. This is me pouring oil onto the flame — how you can use permit data to find new constructions near completion so you can put in an offer before it lists. You are welcome. It’s insanity out there.

Let’s use Seattle as an example, where homes sell within 7 days on the market.

Seattle actually has a really decent open data program.

The data you want to look for is the building permits. You can download the data and analyze/filter it with your favorite tool. But the built-in building permit map offers decent visualization and filtering off the bat.

Say you are interested in townhomes being constructed — we can set the filter to search for these keywords, and limit the permit issue date to be 2020.

Voila you have all the townhomes that has a permit issued in 2020. Sometimes the descriptions will even contain the orientation if you care about that very much. E.g., “Construct east single-family residence…”.

Once you narrow in on a particular construction, you can then pop over to the Permit and Property Records website and look up the permit number. This will give you a list of all permits filed associated with this address so you can stalk the progress and details of the construction.

Usually if sewer permit is already in place — it may be close to completion. But don’t quote me on that.

You can probably replicate the same process for other cities if they have a decent permit online system. And you can definitely write scripts to crawl/analyze/automate to create listings before they hit MLS/Redfin.

Good luck out there! It’s nuts.

Finally, for fun — a totally unscientific overlay of the townhomes construction permit map (issued in 2021 so far) overlaid with the light rail map. Ballard/Fremont/Wallingford, as well as Central/Beacon Hill definitely seeing a lot of actions.

Alright hope this gets more people interested in data science at least!