[OSM-talk] Topology rules

[Martin Koppenhoefer]

sent from a phone

> On 25. Oct 2017, at 17:36, Gaurav Thapa <gthapa.work at gmail.com> wrote:
> 
> In Nepal we have been trying to make sure that each constructed building has its own footprint and is not connected to a neighbouring structure via a shared wall. We do this as in reality this is the case as each building structure though built next to each other has its own footprint (independent foundation).


yes, you can find both situations: a single dividing wall used by both neighboring buildings (in Europe this occurs mostly with medieval buildings), or each building has its own walls (and foundations), but without a significant space between them (e.g. 2 cm of insulating material). 

I would treat both situations the same and use shared nodes, but maybe wouldn’t object if someone purposefully mapped the latter as 2 almost-touching buildings, although the osm building ways usually describe the footprint of the completed building (i.e. with facades, cladding etc.) and not the raw load bearing structure.

cheers,
Martin