Parts of a Building – Foundation, Columns, Floors, Roof

All 15 parts on the diagram

Show the list

Start here: 8 main parts 8

Roof The entire construction used to close in the top of a building.
Exterior wall Any outside wall of a building.
Story The part of a building between one floor and the next above.
Floor slab (floor) The flat concrete deck of a floor, carried by the beams.
Beam A level member that carries a load across a span.
Column An upright member; it carries loads down to the footing.
Stairway (stairs) A series of steps, with landings, between the floors.
Basement (cellar) A story wholly or partly below ground level.

Other 7

Parapet The part of the outside wall that rises above the roof line.
Window An opening to the outside that gives light and air.
Partition An inside wall that divides the space within a story.
Elevator shaft (hoistway) A vertical enclosed space through the floors, used by the elevator.
Elevator A car that is raised and lowered in guides, in the shaft.
Foundation wall A bearing wall below the first floor; it rests on a footing.
Footing The spread base under a column, wall or pier.

How this list was compiled: Read 2026-09-30; a name is kept only where two of these use it. (1) US National Bureau of Standards, Building Materials and Structures Report BMS91, A Glossary of Housing Terms, https://archive.org/details/glossaryofhousin91subc : footing (the spreading course or courses at the base or bottom of a foundation wall, pier, or column), foundation (the supporting portion of a structure below the first-floor construction, or grade, including the footings), foundation wall (any bearing wall or pier below the first-floor construction), basement and cellar, column, beam (a structural member transversely supporting a load), girder (a large or principal beam), story (that part of a building comprised between any floor and the floor or roof next above), exterior wall (any outside wall), curtain wall (a nonbearing wall between columns or piers), partition, roof (the entire construction used to close in the top of a building), parapet wall (that part of an exterior wall extending above the roof line), window, stairway (a series of steps, with or without landings, usually between two or more floors), elevator (a hoisting and lowering mechanism equipped with a car which moves in guides), shaft (a vertical enclosed space passing through at least one floor and used for elevators and the like), lobby, skeleton construction. (2) US Navy, Builder 3 & 2, 1981, https://archive.org/details/ERIC_ED210471 : large multistory buildings are constructed with concrete footings, foundations, columns, walls, girders, beams, joists, floors and roofs; floor slabs; foundation walls; basement; exterior walls; partition walls; parapet; stairways and stairwells; elevator shafts or hoistways; windows. (3) FEMA, A Guidebook to FEMA 154, 1994, https://archive.org/details/ERIC_ED438696 : multistory buildings, columns and beams, the floor deck or slab, exterior walls, curtain walls, masonry partitions, parapets extending above the roof, stair and elevator cores, basements, windows. The Wikipedia request for Building returned nothing in the time allowed, so Wikipedia is not a source here. Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. Licence: own work

How it works

Cut a building down the middle and the same parts show in almost every one: a foundation in the ground, a frame of columns and beams, floors, walls and a roof.

Read the full guide

In the ground

A footing is the wide base that spreads the weight of a column or a wall onto the soil. Foundation walls stand on footings and enclose the basement, the story below ground level.

Above the ground

Columns carry the weight down. Beams span from column to column and hold up each floor slab. A story is the space from one floor to the next. Exterior walls close the building in, and partitions divide the space inside. The roof closes the top, and the parapet is the low wall round its edge. A stairway, and an elevator in its shaft, join the floors.

In a framed building the columns and beams carry the load. An outside wall that carries nothing but itself is a curtain wall.

Questions and answers

What are the main parts of a building?

The foundation, which includes the footings. The frame of columns and beams. The floors, the exterior walls and the roof. Stairways and elevators join the stories, and partitions divide the space inside each one.

What is the difference between a column and a beam?

A column stands upright and carries weight down to the foundation. A beam lies level, spans from one support to the next and carries the floor above it. A large or principal beam is called a girder.

What is the wall around a flat roof called?

A parapet. It is the part of the exterior wall that rises above the roof line, and it guards the edge of the roof.

What is a story in a building?

The part of a building between one floor and the floor or roof next above it. The first story is the one whose floor is nearest the ground at the main entrance, and the rest are counted upward.