How Do I Build

Without it grouping things together in a collection as a building. I then can't delete any part of it later as it deletes the whole thing.
If you click on a building and then find the pencil icon in the top right corner you can edit the building - when you click on that, select whichever single item attached to your building you want to delete and you will be able to isolate and delete that single piece. Alternatively, if you want to copy or delete certain parts of a building, hold CTRL and left click the items you want to select and then simply copy or delete them - or move them. Hope this answer helped you.