Modern toilets incorporate many elements of Haas' water closet designs. Additionally, there is are important ADA requirement of clear floor space at water closet rooms. He lives in a pipe in the upstairs water closet of the Palace. Benjamin King built the first White House water closet/toilet. This model also sports a water closet. American plumbing codes refer to a toilet as a "water closet" or a "WC". It was placed in a water closet formerly used by Winston Churchill. Instead, a special closet auger (from "water closet") should be used. Related forms include earth closet and water closet (W.C. or flush toilet). By the 1830s the water closet was widely used in London. By 1821 the water closet was located adjacent to the staircase. It came with a private water closet, shower, and the ability to sleep six. The name comes from the term "water closet", the traditional name for a toilet. The National came out as the market place's most popular wash-out water closet. The water closet overloaded the medieval cesspool system which was still in use.