Elegant Structures: Diagrids take to the Sky

The word "diagrid" is a blending of the words "diagonal" and "grid" and refers to a structural system that is single thickness in nature and gains its structural integrity through triangulation. Diagrid structural systems have enabled significant transformation in the design of tall buildings. Diagrids are unique in their ability to assume all of the lateral and gravity loading of towers up to at least 50 storeys in height, eliminating the need for traditional columns and cores. Even in Supertall towers it is possible to reduce or eliminate dependence on the core in the top 15% to 30%, allowing for unique spatial opportunities.

The author presents a methodology for the design of diagrid structures based upon the systematic analysis of major buildings constructed from 2004 to the present as documented in her recent book "Diagrid Structures: Systems, Connections, Details" published by Birkhäuser in 2014.[1] The design of diagrid towers will be demonstrated as based upon primary choices in module size, member type, node design, function of the core and the desired expression in the fa9ade system. These translate into additional concerns of constructability and customized fabrication. Fire control systems will impact the ability to architecturally expose or conceal the steel, leading to detailing decisions.