A city or a town has many buildings and structures which cannot be depicted in detail in maps or sketches. To show a complete layout inside a building we make a drawing called a plan. These are normally made by the architects who design houses and buildings. When a house is constructed or a building is planned, architects first make detailed plans or layouts to show how they are going to be constructed. These depict the actual sizes of rooms, the location of staircases, doors and windows and so on.