Hi. Just built my new 4x2 with upper deck approx 1x5 and my 2 piggies just love it. I put carpeting on half of the top with 2 hidies which they both fight over and the rest is coroplast where I put their food, water and hay. This way I can just pick up the coroplast and clean it. I realize though that the coroplast is very slippery for them, when startled they dart and they slip and slide as they run, also very noisy. Anyway once I showed my girls where there food was they now practically live up there. They prefer the upper deck. As a matter of fact one of my girls actually was sprawled out on the carpeting and let me come over and just continuously pet her. That was worth it all. I think they use the downstairs as a large potty toilet. Anyway just want to let you know my girl piggies and I say thankyou for the idea of a c&c cage. By the way you dont realize how big a 4x2 actually is until after you build it. Its rather quite huge.