Huge when talking about the normal Z kits. My National Orange Packing has a foot print of 8x17...the Ice houses are bigger. The wharehouses that will form scenic flats are 18" long and 12" high. In a 6 foot stretch I was able to fill the center line using 8 buidings with narrow alleys between them for the most part. I think small structures in Z are ok, but I would rather fill a module with an industry then random landscaping.