Found this on a OSM forum, might be Sweden only. By user Alexey_Guskov

Hi all,

I print and sell 3D city maps, and while doing my own neighbourhood I realised how thin OSM’s building data is in Sweden. Almost no roof shapes, hardly any building:part, no towers or spires. The churches in Gamla Stan are single blocks with a slightly taller one next to them for the spire :)

I tried JOSM and a few others but ended up writing my own editor, to make it easy to split a building into parts, add tower segments with min_height, set roof shapes, and double check the 3D result before uploading.

Nothing is traced from external data. Esri World Imagery and Lantmäteriet’s Laserdata Skog (CC0) are shown as reference layers, over the map and over the 3D preview, which is how I check that a roof or a height is actually right.

(Lantmäteriet’s building data is still on hold for OSM pending permission, so it’s not used.)

So far I got a bit carried away and mapped every building in Hammarby Sjöstad and a few places in Gamla Stan. It is also kinda my first time contributing to OSM. I hope I didn’t mess things up too much, but I’m trying my best. Let me know if I can improve somewhere.

The editor is here, and I’ll be happy if anyone finds it useful: https://buildings.sillygoose.se/#way/1551309876