Abstract: A building formwork module for use in a modular formwork system, the module comprising a first wall spaced away from a second wall, the first and second walls being connected by at least one web extending between the first and second walls, the first and second walls and said at least one web defining a channel extending over at least a part of a longitudinal length of the module, the channel adapted to accommodate fill material during use, the web further comprising at least two apertures spaced apart across the web in between the first and second walls such that during use one or more transverse reinforcing members can be positioned in between reinforcing members received in the spaced apart apertures thereby limiting movement of the transverse reinforcing member there-between during use.