Method for casting a construction element

A method for casting building material to form a construction element using a computer-controlled apparatus, the apparatus having a material deposition head in communication with a reservoir of formwork material and being movable within a build volume of greater than 1 m3 responsive to computer instructions, the method comprising the sequential steps of:

• (a) receiving, by the apparatus, computer instructions relating to a formwork geometry;
• (b) responsive to receiving the computer instructions, moving the material deposition head within the build volume and depositing the formwork material, from the deposition head, in specific locations defined by the computer instructions to progressively build up a formwork corresponding with the formwork geometry, such that the formwork defines a shell at least partially covering a scaffold structure, the scaffold structure comprising a plurality of interconnected braces defining a plurality of voids, and the shell defining a three-dimensional casting surface;
• (c) applying one or more portions of composite material to the formwork in specific locations, defined by the computer instructions, to at least partially cover the casting surface;
• (d) at least partially covering the casting surface and/or the one or more portions of composite material with the building material;
• (e) at least partially curing the building material in contact with the casting surface so that the at least partially cured building material bonds to the one or more portions of the composite material and forms the construction element;
• (f) removing at least a portion of the formwork from the construction element;
• and then
• (g) collecting the formwork material removed from the construction element and recirculating the removed formwork material to the reservoir to allow the removed formwork material to be re-used, by the computer-controlled apparatus, to fabricate a further formwork.