We currently have a 2x3.5 with a 1x3.5 loft. I've been trying to figure out if there's a spot in the main part of our house where I could put in something slightly bigger, but this works for now. I made it so both the loft and main area have the front swing open for easy cleaning. I put the ramp on the exterior to give them more running room and to also make it easier to clean. To solve the size issue for now I cut an opening in one of the grids and have a removable ramp that they can use to get to the floor for floor time and extra running room. I have a second grid that we attach to the inside to cover the opening when the ramp and playpen aren't in place. ( I just realized I put the bottom coro in backwards, usually it's flush with the opening for the ramp).