What do you think of The Sims 4 on PS4/Xbox One?

I've created some really beautiful women in this game.

The problem I have is I want to create split-level staircases and unless I alter the foundations, it can't be done. A tutorial video said you can create one by doing this but then if you want to make the house higher off the ground, you can't.

Now, if you can create a staircase using normal walls, why can't you create an enclosed area using half-walls, build a deck on top of it and have the stairs go up to that??