35 inches long, almost 21 inches deep. Each individual room is about 10x10 inches, or maybe 11x11 inches. ~9in tall without roofs, 13-14in with roofs. Do 14x11in for the patio, ~ 20in for the pool. The gates add about another 5in to the front.
Some numbers are more accurate than others, but I have to leave for work now.
I rounded up since its better that way for something like a shelf. The more room the better!