As indicated in the question, I am looking for all kind of information about buildings in Switzerland, preferably using an API. This could include information like whether a restaurant or a bank is located in this building or (if possible) information about when it was built.
Two possible sources I have in mind are using the Google Places API or the OSM API. However,concerning the Google API, I am a little bit concerned that the daily requests are limited. But since I don't have much experience in this area, I would very much appreciate to benefit from your experience.