Please help - Walls disappear and roofs are looking funny

What am I doing wrong with 3d buildings? The walls disappear under roofs, building parts above ground level are not rendered and roofs are just looking weird.

I think I have followed the directions for simple 3d buildings in the wiki - but apparently not good enough.

Simple building with disaapearing walls:

Complex building with a lot of issues: Disappearing walls, roofs pointing in the wrong direction, above-ground building parts not rendering etc.:

Here the onion domes are not rendered:

I would be really happy if someone could help.

Tårnborg looks good to me, can you provide a screenshot ?

cathedral : i’ll need to investigate. but you need to specify skillion direction. my guess is using building:part roof disables wall rendering, you may want to try with building:part yes (or add another part)

onions : you specified building levels, but not roof levels (or height)