The basic idea is to have multi story apartment blocks. First you have your city laid out, with your apartment block somewhere.Have a location or whatever for entering it.When a unit hits that location, it is teleported to an area off the normal playing area, with walls/cliffs/whatever surrounding it to make it look building shaped.
Inside that area, you have a door for exiting, plus indoor stuff like beds, TV's etc. You also have terrain/a unit for the staircase. When the unit goes into that location, you teleport him to another area reserved for this purpose, then remove all the beds TVs etc.Using preplaced locations(probably laid in a grid all over the floor) you then use triggers to place more beds TVs couches etc. at different locations.
When the player gets to the top story, you can teleport him to the city at the top of the building he entered. Obviously this gets quite complicated the more stories/apartments you have, but it should still be usable.
Hope this is useful to someone.
Red classic.
"In short, their absurdities are so extreme that it is painful even to quote them."
"In short, their absurdities are so extreme that it is painful even to quote them."