Methods are provided for repairing an existing structure to cover at least a portion of the existing structure with a repair structure. Such methods comprise mounting one or more standoff retainers to the existing structure; coupling one or more standoffs to the standoff retainers such that the standoffs extend away from the existing structure; coupling one or more cladding panels to the standoffs such that the panels are spaced apart from the structure to provide a space therebetween; and introducing a curable material to the space between the panels and the existing structure, the panels acting as at least a portion of a formwork for containing the curable material until the curable material cures to provide a repair structure cladded, at least in part, by the panels. Corresponding apparatus for effecting such methods are also provided.