On one end of the hole, a bedroom and closet. The other end is the bathroom. The gas water heater was in the kitchen before my parents bought the house. The Federal Housing Authority told the previous owners no way, you're not selling until you move that water heater out of the house due to carbon monoxide dangers. The house next door apparently has it in the house still. Nobody was living there when it busted and it caused a disaster. So I'd never find anyone that would do such a thing legally now. So that's hon this hole and wall were built. They built the wall in a half-butt kind of way, too. I'm going to search around and see if I can special order one. The only issue might be finding a company willing to install it when I bought it online.