I believe from my memory that I can build four 30"x45" modules with about 200 of the blue tubs. It would build 3 normal modules and one 2x4/2x6 hybrid module. The hybrid would use 2x4 for the walls and 2x2 for the towers, but use 2x6 for the lattice (...) (24 years ago, 16-Dec-00, to lugnet.trains)