Either all ways below roof or the roof should get a layer tag.
Osm roof shapes.
If there are already other features below or above the roof on the map layer should be used to provide information about stacking of features.
After the roof shape has been drawn it should be moved to match the location on the ground level.
In case of ways below the roof.
In addition covered may be used to mark objects for example roads as covered by the roof.
How to identify rooftop in osm.
Hipped left and gabled right roof shapes.
How to tag roof orientation for roof shape side hipped and similar roof shapes.
However they all seem to be mostly symmetric.
This section is a wiki template editable here.
Additional roof shapes are suggested in s3db proposals including advanced approaches for manual modelling e g proposedrooflines or parts of osm 4d roof table.
I have heard that we can do that in osm.
0 i am trying to identify rooftops of all buildings for a part of a city.
Simple 3d buildings on the osm wiki defines several roof shapes.
This should be self explaining.
Draw along the outline of the roof apply rectangularization e g.
Josm q key if so desired.