Abstract: In a first aspect there is disclosed building panel (100) for forming a load-bearing structure. The building panel (10) comprises a backing member (102) and a strengthening element (104) mountable to the backing member (102). The building panel (100) further includes a void former (110) mountable to the backing member (102) and disposed adjacent to the strengthening element (104) for forming a void (112) in the structure wherein the backing member (102), the strengthening element (104) and the void former (110) are configured to receive a mixture curable to form the structure.