|building = roof|
|A building open on at least two sides.|
|Used on these elements|
|Status: de facto|
|Tools for this tag|
How to map
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. In addition covered=* may be used to mark objects (for example roads) as covered by the roof.
In case of ways below the roof:
- either all ways below roof or the roof should get a layer tag. In more complex situations layer=* for roof, ways under roof and for other objects may be required.
- The way may have shared nodes with the building where it crosses the outline of the building.
- The way should be tagged with covered=*. When the two walls of the building=roof form a tunnel without an open side use tunnel=building_passage instead.
- building=* + wall=no is in use for buildings without (some) walls
- man_made=canopy is in use for canopy like roofs
- building=carport is proposed in Proposed features/carport buildings
- It has also been suggested that A porte-cochère or carport should be mapped as a building:part=carport area within the main building area rather than as a separate building=carport or building=roof area.
Usage in Sweden
This is a minor import but: This tag was recently used in an import in Sweden; It was used to denote, among other things, buildings that have two walls or less. This means can mean e.g. a front porch. So when it was surveyed the buildings had two or less walls, but it's noted that new walls can later be added by the owners and the data can not be 100% on what the current state is.