Are you referring to real estate listings? In my case, I use Trulia to search the zones after I narrow down the locations. However, if you're referring to the

Are you referring to real estate listings? In my case, I use Trulia to search the zones after I narrow down the locations. However, if you're referring to the building footprints I have a Make target that pulls GIS data from public sources: https://github.com/caged/portland-atlas https://github.com/caged/portland-atlas