Simplified space frame roof with the nearest unit polygon hightlighted in blue

A space frame is a truss-like, light weight rigid structure constructed from interlocking struts in a geometric pattern.

The simplest form is a horizontal slab of interlocking square pyramids built from aluminium or steel tubular struts. In many ways this looks like the horizontal jib of a tower crane repeated many times to make it wider.

A stronger purer form is composed of interlocking tetrahedral pyramids in which all the struts have unit length. More technically this is referred to as an isotropic vector matrix or in a single unit width an octet truss.

More complex variations change the lengths of the struts to curve the overall structure or may incorporate other geometrical shapes.

They derive their strength from the inherent rigidity of the triangular frame; flexing loads (bending moments) are transmitted as tension and compression loads along the length of each strut.

Space frames were independently developed by Buckminster Fuller in the 1950s and Alexander Graham Bell around 1900. Bell's interest was primarily in using them to make rigid frames for nautical and aeronautical engineering although few if any were realised. Buckminster Fuller's focus was architectural structures and has had more lasting influence.

Space frames are an increasingly common architectural technique especially for large roof spans in modernist commercial and industrial buildings.

Notable examples of buildings based on space frames are:

• the airports of Foster Associates, for example Stansted Airport
• Ieoh Ming Pei's entrance Pyramide du Louvre.
• Few complex & attractive Space Frames

• the roof of the Skydome by Rod Robbie and Michael Allan

The space frame roof at Stansted Airport

Larger portable stages and lighting gantries are also frequently built from space frames and octet trusses.

Tubular space frames are also widely used in the production of modern automobiles, but monocoque have been more common in the latest 50 years.