Abstract: A retrofit adaptor is provided for retrofitting a glazing structure comprising an inner frame body and an outer frame body with windowpanes therebetween forming a glazed window. The retrofit adaptor comprises outer and inner connecting elements and a thermal break interposed therebetween and connected thereto. The outer connecting element for being connected to the outer frame body and defines an outer clearance hole therethrough. The inner connecting element for being connected to the inner frame body. The thermal break defines a cavity for receiving insulation therein. A mechanical fastener is insertable through the outer clearance hole of the outer connecting element when unconnected to the outer frame body and through the inner connecting element when mounted to the inner frame body, via the cavity, for being fastened to the inner frame body. The outer frame body is connectable to the outer connecting element for closing the outer clearance hole.