A building side kit is provided where the siding board is attached to an insulation board from their upper edges and a one step installation of the kit is provided with attachment clips. The insulation boards may have interlocking male extension and female deeps on their upper and lower edges. Attachment clips fitting with siding board/insulation board assemblies with male extensions on the upper edge of the insulation board are also provided. The system may also include a reflective backing and/or drainage grooves on the back of the insulation board.