The building permit files provide a picture of residential construction activity for each county and city in the state by month or year. Building permits are categorized by type of building (single-family, duplex, 3-4 unit structures, and 5+ unit structures) and by builder-estimated value of the construction. For multi-unit structures, the data indicate the number of units permitted rather than the number of buildings. The information excludes permits issued for mobile homes, garages and other out-buildings, additions and renovations, and commercial construction.

The Census Bureau used to collect data on commercial construction, demolitions, and mobile homes. They have discontinued these surveys and these data are no longer available.