The modern toilets; toilets or toilets use a cistern to reserve and maintain the amount of water required to clean the cup. initially; the cistern was high; located near the roof; and connected to the cup through a pipe. it was necessary to pull a chain connected to a valve located inside the tank; to clean the toilet. modern toilets are conceived as compact units; with the tank attached to the cup; the pipe connecting the tank to the cup has been removed. hidden tanks are also available; where the cistern is placed inside the wall behind the toilet. floor plans - sections - structural development and construction details with technical specifications. autocad - dwg.