This knowledge, plus some time spent digging up my original copy of SimTower and playing it some more, has reawakened my desire to make a tower game. I've had plans to make a tower game for at least six years but it's never gotten off the ground, surprise surprise...
I've been thinking about the data models that would provide a foundation for the game.
I want to beef up the architectural/structural engineering aspect, for one thing. The original SimTower simply operated on "cannot build a floor wider than the floor below" and did not allow gaps in floors (so you couldn't, for example, build twin towers). Yoot Tower apparently allows gaps between sections with "sky bridges" - I don't know to what extent they actually get used in the personnel transport model - but keeps the restriction that floors cannot be wider than the one below them.
Well, I think that's slightly too simplistic for my liking; I'd like to be able to have overhangs on my towers, but more importantly, I'd like to remove the idea that each storey of the building actually has a ceiling and floor. There was a little cheat in SimTower that allowed you to build a three-storey lobby that was a lot more plush and pretty than the basic one; well, I'd like to support 14-storey lobbies, like the Hyatt I once stayed at in downtown San Fransisco. Sitting down at their brunch was like dining in a gigantic cavern; a large skylight at the top let the light in, while balconies snaked around the edges, connecting the doors to the actual rooms. I want to let people build that kind of structure. However I also want to let people just get up and running with a tower quickly.
I think what I'm currently pondering is quite like the building model in the Sims games, just extended to an unlimited number of floors. You build walls with the same kind of ease - you can choose between 'strong' walls and regular walls, regular walls being cheaper - and then you can place floor tiles on top of the walls, up to a given distance away from the wall (distance depending on type of wall). Supporting pillars and columns can allow you to extend that distance further; there will also be some elements that work up-side down, allowing you to build flooring that is anchored to the ceiling instead of being held up from underneath.
I think that will allow flexibility without overcomplicating things. If you want you can just grab the strong walls and draw a box with a few pillars here and there, then cover it in floor/ceiling, then 'repeat this floorplan' for twenty floors (automated duplication). Using strong walls for everything would be slightly more expensive than regular walls, but not massively so - regular walls might be $1 per section while strong walls might be $3.
However, if you wanted to rebuild the Hyatt in San Fransisco, you could set up two rings of strong walls at the outside, segment them with further connecting strong walls, then build ceiling on top of the ring. Duplicate that upwards and you get a ring of well-supported compartment rooms around the outside of the tower and a huge cavernous middle.
I'm not sure how I'd do the skylight though. Perhaps it would just be a special floor tile that can be placed further away from walls than regular tiles and cannot have anything built on top.
It's worth noting that this would also permit overhanging structures on the outside of the building - there's no differentiation made between internal and external walls except perhaps in rendering.