Ground plan

In architecture and building engineering, a floor plan is a drawing to scale, showing a view from above, of the relationships between rooms, spaces and other physical features at one level of a structure.

Dimensions are usually drawn between the walls to specify room sizes and wall lengths. Floor plans may also include details of fixtures like sinks, water heaters, furnaces, etc. Floor plans may include notes for construction to specify finishes, construction methods, or symbols for electrical items.

It is also called a plan which is a measured plane typically projected at the floor height of 4 ft (1.2 m), as opposed to an elevation which is a measured plane projected from the side of a building, along its height, or a section or cross section where a building, is cut along an axis to reveal the interior structure.

Similar to a map the orientation of the view is downward from above, but unlike a conventional map, a plan is drawn at a particular vertical position (commonly at about 4 feet above the floor). Objects below this level are seen, objects at this level are shown 'cut' in plan-section, and objects above this vertical position within the structure are omitted or shown dashed. Plan view or planform is defined as a vertical orthographic projection of an object on a horizontal plane, like a map.

The term may be used in general to describe any drawing showing the physical layout of objects. For example, it may denote the arrangement of the displayed objects at an exhibition, or the arrangement of exhibitor booths at a convention. Drawings are now reproduced using plotters and large format xerographic copiers.

A reflected ceiling plan (RCP) shows a view of the room as if looking from above, through the ceiling, at a mirror installed one foot below the ceiling level, which shows the reflected image of the ceiling above. This convention maintains the same orientation of the floor and ceilings plans - looking down from above. RCPs are used by designers and architects to demonstrate lighting, visible mechanical features, and ceiling forms as part of the documents provided for construction.

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