Segment

A segment is the width of the floor tool. All rooms and objects require a certain number of segments to be constructed on the floor below them in order to be placed.

Game Map
The game map is 375 segments wide.

Rooms and Objects
The Cathedral is the only room that can be built on level 100. The Metro Station requires 3 levels, can only be built underground, and cannot have anything built on it's bottom level or underneath it.