Abstract: The present invention provides a fastener assembly (20) for a prefabricated service module. The fastener assembly (20) comprises a first arm (21) having a flange (211) at a first end (221) thereof; a second arm (22) having a flange (221) at a first end (222) thereof; and a retainer mechanism (23). The second arm (22) is arranged parallel and opposite to the first arm (21); and the flanges (211, 221) of the first and second arms (21, 22) are arranged opposite from one another and extend in a direction away from each other. The first end (212) of the first arm (21) is moveable between a first position wherein said first end (212) is spaced apart from the first end (222) of the second arm (22) at a first distance, and a second position wherein said first end (212) is spaced apart from the first end (222) of the second arm (21) at a second distance, the first distance being greater than the second distance.