Living in a big city apartment with limited space requires one to procure inventive accommodations for when friends visit. The DOC sofa from Clei UK offers inventiveness in spades: It literally converts into a bunk bed. The sofa is made from tubular steel painted with epoxy powder and features an opening mechanism with gas pistons. To top things off, the cushions/mattresses offer  fully removable covers that are machine washable.  It comes in various colors and two sizes.