User talk:Mateusz Konieczny/ruined building

no roof - not a building

It is not a building if it has no roof, both according to OSM wiki definition of building=* (as it fails "man-made structure with a roof, standing more or less permanently in one place"), and to common understanding of the term as in building "enclosed structure with a roof and walls standing more or less permanently in one place". And when it is not a building, it should not use pure building=* tag anymore, but a different one (e.g. lifecycle prefix) .

I.e. if the people are not living inside (nor is it usable as such, e.g. for squatting, or hiding in case of zombie apocalypse), it probably should not be tagged as building=* (additional tags notwithstanding).

I'd suggest:

• abandoned:building=* for significant amount of damage which disqualify it as a building (e.g. collapsed roof with missing doors and windows). I.e. when it can be "put back into safe operation with expensive effort, such as completely rebuilding the roof or walls".
• ruins:building=* for even higher amounts of damage e.g. like only some or even only one of the walls remaining, or even just basically a heap a bricks only some of which are maybe still standing. (i.e. it is beyond repair)

ruins=yes especially smells like a trolltag for those cases, and should IMHO be avoided whenever possible. Either it is a building, or it is a ruins of one. It can hardly be both at the same time, IMHO.

Updated abandoned:building=* has some gallery, comparisons and explanations that might help with this effort. Let me know if you'd like more feedback. --mnalis (talk) 16:33, 5 May 2023 (UTC)

I think that sham ruins isn't a building also. man_made=ruins or man_made=sham_ruins may be alternative. Something B (talk) 08:21, 23 June 2023 (UTC)

Alternative tags

Building is gone, but present in usable sources

• no:building=*
• not:building=*

Something B (talk) 09:12, 23 June 2023 (UTC)

Note that such building only would be mappable if there is a real risk of being mapped by accident (still visible on aerial imagery etc). If for example cadaster has fake/outdated/bogus data that is not a valid reason to copy them to OSM and mark as nonexsting (in case of repeated import it may be useful to have list of entries to be skipped, but it should be maintained as part of import bot and data conflation process) Mateusz Konieczny (talk) 13:13, 23 June 2023 (UTC)

AFAIK, some cadasters are available for tracing or otherwise available for ordinary mappers, and wrong outlines may be added by accident - similar to tracing of aerial imagery. Something B (talk) 15:44, 23 June 2023 (UTC)

In such case there is still aerial Mateusz Konieczny (talk) 16:45, 23 June 2023 (UTC)

Then it's a matter of terminology. :-) Something B (talk) 18:25, 23 June 2023 (UTC)

As a sidenote: while no:*=* might be useful (as may was:*=* or removed:*=* / razed:*=* etc.), note that not:*=* has different use-case - it is for differentiating similarly looking things (e.g. area might look like a building roof from a lower quality aerial, but is in fact private car parking with shadow - in that case you'd tag it as amenity=parking + access=private + not:building=house) --mnalis (talk) 22:55, 19 June 2024 (UTC)