Automatic roof in build mode. Unless you are building a rectangular box the result o f automatic is usually dreadful.
I do a lot of building, but somehow, must be my age! I forget to dissable automatic roof before I start. I build the ground floor and try to add stairs, and of course, I get the message, can't place stairs. I realise immediately that the roof is in the way, so I take it off and then place the stairs. Then I realise that the ground floor is not quite right, so I use the undo, make my little adjustments, then try to place the stairs. Yes, I also undid the roofs off. So, I go to roofing menus again and select roof off, place my stairs and start on the first floor. Then I decide on a little alteration to the ground floor so, I use undo .................................................. grrrrr!