The documentation for Chicago's building permit data seems to be out date. Anybody know what Permit Type "PERMIT - NEW CONSTRUCTION" and "PERMIT - RENOVATION/ALTERATION" mean?
Those are pretty common terms for building permits.
"New construction" means that they're building (or placing) a new building.
"renovation/alteration" means that there's an existing building that's being modified.
What qualifies as a renovation can get a little interesting by area ... I remember one of my co-workers telling me that in Virginia if you leave one wall standing, you can declare it to be a renovation, and avoid having to pay all of the fees required for new construction if you're looking to tear down an existing building.
See the city's website for details on the other permit types.