Collapsible formwork for concrete walls

A collapsible formwork element, the element including:

• a pair of opposing side wall panels each formed of extruded polymer material;
• and
• at least one connector member extending between the side wall panels, the at least one connector member formed of extruded polymer material,
• wherein the at least one connector member includes a centre portion between a pair of hinged ends provided by hinge portions in the connector member, wherein the hinged ends are engaged with the side wall panels such that the element is movable between an expanded configuration, wherein the opposing panels are spaced apart, and a collapsed configuration, wherein the opposing panels are relatively closer together, and, on expansion into the expanded configuration, the formwork element is mechanically maintained in the expanded configuration, and
• wherein the lateral ends of the opposing side wall panels include engagement portions for engagement with like collapsible formwork elements so as to allow formation of a formwork structure comprised of a plurality of the collapsible formwork elements, wherein the engagement portions are configured to provide snap lock engagement between neighbouring formwork elements.