By replacing orthogonal concrete moulds with a system formed of flexible sheets of fabric it is possible to construct optimised, variable cross section concrete elements that can provide material savings of up to 40% when compared to an equivalent strength prismatic member, and thereby offer the potential for significant embodied energy savings in new concrete structures. This paper provides pointers on some research undertaken at the BRE Centre for Innovative Construction Materials (BRE CICM). The work demonstrate that a fabric formwork construction system may be used to facilitate a sustainable future for concrete construction, providing a design method by which structurally optimised elements may be cast in an economical manner while also providing significant durability and visual benefits.