Diagrids

Diagrids, or diagrid structures, are a structural system in which the primary framework is formed by a network of diagonally intersecting members that create a triangulated lattice. The lattice may act as an external exoskeleton around a building or as an internal framework, and is typically composed of steel or reinforced concrete members joined at nodes.

The diagonal grid provides multiple load paths and high stiffness, enabling tall or slender buildings with fewer internal columns. Triangulation distributes wind and gravity loads efficiently, allowing greater cantilever freedom on upper floors and more usable floor area. The system can reduce total material usage by optimizing member sizes, though fabrication and connections are more complex.

Design variants include external diagrid exoskeletons, internal diagrid bracing, or mixed configurations that combine diagonals with conventional vertical frames and a central core. Diagrids are often used with curtain walls or cladding that follows the diagonal geometry.

Construction and engineering considerations include precise fabrication of diagonal members, junctions, and connections; tolerance control for the lattice; and integration with enclosures, elevators, and services. The system can alter dynamic response to wind and seismic loads, sometimes requiring dampers.

Notable examples include the Gherkin in London, designed by Foster and Partners, which popularized the external diagrid, and the Hearst Tower in New York, which uses a diagrid exoskeleton to support a tall, lightweight tower atop a historic base.

Diagrids are a prominent tool in modern high-rise design, balancing material efficiency with distinctive architectural form.