This twin over twin house bunk bed frames both decks with a pitched roof and a cut-out front window, giving two children a playhouse that doubles as a bedroom. Twenty-one plywood slats split between the levels rate each deck at 350 lbs, so the lower bunk is a real bed rather than a play space. Guardrails run 12 in around the top, and a 15-in by 10-in entry lets a child climb the integrated ladder without twisting. There is 33.5 in of headroom between decks, enough for a child to sit up on the lower bunk. Both levels take a mattress up to 6 in thick.