Recently, I saw a diary post about Microsoft releasing US building footprints, and I wondered how they could be used to add buildings to OSM in my favorite editor. I quickly found out that large files won’t load in iD. I searched for a tool that could make the files smaller and usable and found one called geojsplit.

I took it upon myself to examine the code of that project, to learn a bit of JavaScript, and to form it into a tool more suited to my needs. Large database files won’t load in iD, but they can be made smaller in size by omitting features outside the viewing window of the editor. As a result, I can now see the building traces in my favorite editor. :)

I think if I use another editor like Potlatch, I can just click on the footprints/traces while holding down Ctrl or Shift to import the buildings one by one.