The present invention concerns an insulating wall system for a building structure, wherein said wall system comprises a first wall having an exterior surface with insulation material fitted to said exterior surface of said first wall and retained by at least one elongated support member abutting the insulation material which via fastening members extending through the insulation material substantially perpendicular to the exterior surface is anchored in the first wall, and wherein the elongated support member comprises an elongated beam with one or more nail plates mounted on the insulation abutting inner surface of said beam for enhancing friction.