Abstract: An insulation panel (1, 601) is used as exterior wall insulation cladding affixed to the external walls of a building via fitting section or fastening flange (8, 608) of the panel (1, 601) which includes screw slots to allow simple installation. The panel (1, 601) consists of an outer layer or front surface (2, 602) of thermoplastic or other suitable material that provides weatherproofing, is durable with low conductivity and an efficient inner insulation material (7) consisting of a closed cell thermal insulation material in a cavity (6, 606). The panels (1, 601) are aligned and attached together by tessellation. The panel (1, 601) is extruded or injection moulded or formed by any other process suitable for this application. Internal features (15, 615) can include connecting bridges for added rigidity. A rear surface (3, 603) of the panel (1, 601) may feature air and moisture vents to disperse trapped moisture and gas between the wall face and the rear (3, 603) of the panel (1, 601).