Typical lightweight structures include cable-, membrane-, shell-, and folded structures as well as space grids, braced vaults and domes, arched-, stayed-and trussed systems. Membrane materials are commonly PVC-coated polyester fabrics as well as PTFE coated glass. Lightweight structures are widely employed in architecture, engineering and building construction and find application in long span roofs for stadiums and exhibition structures; covered shopping malls; entrance structures; signature structures and sculptures as well as shade and environmental protection canopies.
While it is difficult to assign a single all-encompassing definition of a Lightweight Structure, the following description should suffice: "A lightweight structure can be termed as such, when, regardless of the type of material employed, the shape of the structure is determined through an optimisation process to efficiently carry the loads from a critical loading case."
Normally the self-weight of the structure is a small portion of the applied load or generated forces. Lightweight structures often utilise lightweight and high-strength materials as well as advanced technologies for their design and construction. For many forms, the surface is prestressed and this results in doubly curved shapes requiring specialized cutting patterns and care during erection. They are recognised for their aesthetic appearance and their innovative character.