|building = ruins|
|Frequently used to mark ruined buildings. However, this usage conflicts with general use of building tag. In theory it should only be used for buildings constructed to look like ruins.|
|Rendering in OSM Carto|
|Used on these elements|
|Status: in use|
|Tools for this tag|
The tag building=ruins is frequently used to mark abandoned, ruined buildings. However, according to the meaning of building=*, this tag should be used for a building constructed as ruins (for example sham or scenic ruins in an English landscape garden). Frequently the use of this tag is in conflict with other building=* values, for example, building=ruins used for a house that is abandoned (but still is a building) conflicts with tagging it as building=house.
Due to this it is a good idea to explicitly mark construction as sham ruins (for example with note=*).