What is an overhead diagram depicting the structure's walls, doors, and stairs called?

A floor plan is a detailed and scaled diagram that illustrates the layout of a building's rooms or spaces from a top-down perspective. It includes essential features such as walls, doors, windows, and stairs, allowing the viewer to understand the spatial arrangement and flow of the structure. This type of diagram is fundamental in various fields, including architecture, real estate, and firefighting, as it provides critical information regarding access points and potential obstacles within a building.

In contrast, an elevational drawing presents the exterior views of a building from the side, showing height and architectural details but not the internal layout. A site plan encompasses the broader context of the building’s location, typically including landscaping, driveways, and external structures, rather than focusing in detail on the building’s interior configuration. A cross-section diagram offers a view of the interior as if the building has been cut through vertically, showing internal layers and structures, but it does not showcase the entire layout like a floor plan does. Thus, a floor plan is the most appropriate term for a diagram that outlines the walls, doors, and stairs of a structure from an overhead view.