I messed with doing something like that early, and then decided it's a
lot easier to build on one of the bare foundations. The ones you get when you scrap an entire house. There's one right next to the Workshop house.
What about crafting areas you say? Well, just pick 'em up and move 'em. Even if you have no Local Leader Perks, you can move stuff you're not allowed to build.
Note that this is just my workshop and mall area. It has a high ceiling so it can fit shops. I've only got a couple of beds in there, for my own convenience. Most of my beds are in the existing housing, because I put 'em there when resources were still short. I
could put lots of beds up in the balcony area, or create another floor.
The main problem with doing a central Arcology style settlement with turrets on top of your main housing is that the beds are near the turret noise. Supposedly that's bad for happiness.