Structure of a Building

The primary structural and architectural components of a multi-story building from foundation to roof.

• Footing: The widened base of a foundation that distributes structural loads directly onto the underlying soil or rock.
• Foundation Wall: A below-grade structural wall that supports the superstructure and transfers loads to the footing.
• Slab: A flat horizontal concrete surface forming the ground floor or basement floor.
• Column: A vertical structural member designed to carry axial compressive loads from beams or floors above.
• Beam: A primary horizontal structural member spanning an open space to support loads applied transverse to its axis.
• Floor Joist: A horizontal repetitive framing member that supports the floor subfloor and finishes.
• Subfloor: The structural sheet or planking attached to joists upon which finish flooring is laid.
• Load-Bearing Wall: A vertical wall designed to support the vertical weight of upper floors or roof systems in addition to its own weight.
• Partition Wall: A non-load-bearing interior wall used primarily to divide space into rooms.
• Lintel: A horizontal structural beam installed across the top of a door or window opening to support the wall above.
• Sill: The horizontal structural member at the bottom of a window frame or the bottom plate of a framed wall.
• Ceiling Joist: A horizontal member spanning between walls to support the ceiling finish and tie exterior walls together.
• Roof Truss: A prefabricated triangular framework of timbers or metal supporting the roof covering across long spans.
• Rafter: An inclined framing member extending from the ridge or hip of a roof to the eaves, supporting the roof deck.
• Roof Sheathing: The layer of boards or panels applied over rafters or trusses to provide a base for waterproofing and shingles.
• Parapet: A low protective wall extending above the edge of a roof, balcony, or terrace.
• Eaves: The lower edges of a pitched roof that project horizontally beyond the side of a building.