I have a 14ft 100lb Burmese that I house in a 6ftx3ftx18in vision cage with no problems and he seems to have plenty of room. The 36in width allows me to put a rubbermaid container large enough for him to soak in. I think anything smaller would not allow him enough room. I also have a med size Helix radiant heat panel on one side that keeps the temp at about a constant 84 degrees then I use a basking light on one side to get the temp up to 90-92.