[Tagging] building:levels and flat roofs

[Tobias Knerr]

On 03.10.23 at 07:24, contrapunctus wrote via Tagging:
> 1. What value should be given to building:levels=*?
> 
> 2. Should roof:levels=* be used? If so, how?
[...]
> [1] https://wiki.openstreetmap.org/wiki/File:Multi-level_building_with_flat_roof_in_Adarsh_Nagar,_Delhi,_India.jpeg

This building seems to have no "roof level" in the sense of 3D mapping, 
which would be a level within the slanted part of a gabled roof or 
similar roof shape.

(Also, although it's more of an aside, to me B looks as if it's just a 
kind of railing around a platform at the same elevation as A, not a 
separate level below it. If that's the case, the building has only 6 
levels in total.)

So for the purposes of Simple 3D Buildings, I would say this is a 
building with 6 levels and roof:levels set to 0 (or just omitted). The 
building as a whole as well as the tallest building part should be 
tagged building:levels=6, and the second building part would be tagged 
building:levels=5.

Whether you stack the building parts on top of each other (with a 
building:min_level tag on the upper one) or put them next to each other 
is ultimately up to you, although the former feels more natural to me here.