A siding panel product is provided comprising a first polymeric siding panel having a butt end and a top end, a front surface comprising a plurality of front faces defined between the top and butt ends and separated by at least one shoulder surface to define a stepped contour, and a rear surface. An insulation backing is coupled to the rear surface of the siding panel. The insulation backing comprises at least first and second insulation members coupled to the rear surface of said siding panel. The first insulation member has a bottom edge thereof coupled proximate to the stepped contour and the second insulation member has a top edge thereof coupled proximate to the stepped contour.