In architecture and building engineering, a floor plan is a technical or diagrammatic drawing that illustrates the horizontal relationships of interior spaces or features to one another at one level of a structure. They are typically drawn to-scale and in orthographic projection to represent relationships without distortion. They are usually drawn approximately 4 ft (1.2 m) above the finished floor and indicate the direction of north.
The level of detail included on a floor plan is directly tied to its intended use and phase of design. For instance, a plan produced in the schematic design phase may show only major divisions of space and approximate square footages while one produced for construction may indicate the construction types of various walls. Floor plans may indicate specific dimensions or square footages for particular rooms and/or walls. They may also include details of fixtures (sinks, water heaters, furnaces, etc), notes to specify finishes, construction methods, or symbols for electrical items. They may be rendered or drafted.