Another dataset that the city of San Francisco makes publicly available is the Department of Building Inspection's monthly permit report. This report contains all the building permit activity within the city, from permits to add new condos to inspections of sprinkler systems. We took one full year of data, from September 2008 to August 2009, and brought it into SpatialKey. During the selected year-long time period there were over 25,000 permits issued. We can see the breakdown by the type of building on the right. Residential housing takes the top three spots (divided into Apartments, and one and two family homes).
We mapped the concentration of where these permits were issued. The different types of buildings, such as apartments versus office buildings, have very different distributions throughout the city. Some of these distributions are expected, such as the high concentration of permits for offices in the downtown area of San Francsico. But some of the distributions are more interesting and tell a story about the urban makeup of the city. Notice that apartments are much more concentrated closer to downtown in neighborhoods like the Tenderloin, Nob Hill, and Hayes Valley, most heavily around the eastern and northern areas surrounding the financial district. Two-family homes (ie duplexes) have a different concentration that includes neighborhoods like Cow Hollow and the Mission. And one-family homes are in neighborhoods like Pacific Heights, Noe Valley, and Twin Peaks.
The maps here show the number of building permits by the type of building.
Here are some alternate screenshots that are at a more granular resolution, so you can see a bit more detail on the different areas of the city. Click each thumbnail for a much larger version:
Notes on the data
It's always important to remember what data we're looking at. This is the number of building permits issued between September 2008 and August 2009. A single building might have multiple permits issued, which could be everything from renovations or re-roofing to a change from residential to commercial, etc.
The images and reports in this post were created with publicly accessible data. We have no association with the city of San Francisco (but we’d love to, so contact us if you’re from the San Francisco government and want to use SpatialKey).