I would like to create detailed plans of my house. Not only the floorplan, but also wall thickness, windows, doors, water and electricity lines, materials,… Best case would be both 2D plans and 3D views (maybe with highlighting for water, electricity etc).
Do you know of some open source software, that might be able to handle this task?
Having previously used tools like Inventor (which isn’t great for floor plans, but is great for parametric modeling) yes, Sweet Home 3D has a terrible UX. That’s doubtless why you didn’t find out how to adjust walls, etc. parametrically. I wouldn’t classify it as terrible, but it isn’t great, for sure.