[Tagging] Uses of parts of buildings

[Martin Vonwald (imagic)]

Hi,

A quick question how you would tag this: 
* one building (looks from the outside mostly like a residential building)
* the building is used for three different things: an office, a riding ground (just assume it's a pitch) and a stable.
* the building is not separated - it's just one building
* I'm not interested in the detail- tagging, just how you would tag three different uses.

My idea right now is:
* building=yes for the whole building. Or should it be residential?
* for each part draw a separate polygon and tag with building:use=whatever.

What I'm missing here is the connection between the building and its parts. So I thought I could use the 3D-extensions for this, namely building:parts=yes on the main polygon and building:part=yes on the parts.

Comments? Hints? Thoughts?

Thank you,
Martin