For my first day contributing to OSM, I tried to split the building at 55.499, 25.602 into two objects, to reflect recent changes in ownership: half of the building is now privately-owned, and although the two parts still share a wall, they officially have different addresses (due to entrances from different streets).
The result seems to be fine when viewed via JOSM or the web interface:
From what I read in you comment, it is still one building in the real world. Internally it has been split in 2 parts, which can be represented by adding outlines for the internal parts tagged with building:part. The addresses can be tagged on the building parts or on separate address nodes.
So in my opinion, you shouldn’t split this building. Just like we wouldn’t split the Burj Khalifa (Dubai) in over a 1000 separate buildings because there are this many apartment and offices. I know this is an extreme example, but the concept is the same. One building in the real world <=> one building in Osm.
I actually assumed that such splitting is standard practice because of the large amount of instructions on using the Terracer/Uberterracer plugins for JOSM to do this exact thing?
I don’t know if there is such a thing as “standard practice” in OSM, but it is certainly very common. See for example Way: 606066930 | OpenStreetMap and surrounding area in Berlin which has buildings that are connected to each other and which share very similar massing and construction, mapped as separate buildings according to their access details, street address, and I guess ownership.
From the reactions I realize that I was a bit to much focused on the situation in The Netherlands. Here, almost all buildings have been imported form official government sources, so splitting and the Terracer plugin are hardly ever needed.
You can ignore my previous comment.
So I actually looked at official government sources a bit later (that is, when I learned about geoportal.lt, which I believe LT buildings were once imported from).
If I understand this correctly (though it’s likely that I don’t), the official government sources do split the building – the “GPRK” layer shows the same line I drew (coord link):
The land cadaster map has an even weirder split that goes sideways, which doesn’t make any sense for that building’s internal layout, but from what I’ve heard it just…happened somehow:
