An insulation system for coupling to a building substrate comprising: - a plurality of insulation panels, each insulation panel including a front face, a back face and a plurality of side surfaces extending therebetween, the side surfaces including a longitudinal slot extending along at least a portion thereof; - a plurality of bracket members, each bracket member comprising a polymer and including an elongated body having a body wall, a first end wall extending from a first end of the body wall and configured to be attachable to the building substrate and a second end wall extending from the second end of the body wall opposite the first end wall, the body wall having a top surface and a bottom surface, and an upper rib extending upwardly from the top surface of the body wall spaced apart from each of the first end wall and the second end wall, and a lower rib extending downwardly from the bottom surface of the body wall spaced apart from each of the first end wall and the second end wall, each of the upper rib and the lower rib structurally configured to extend into the longitudinal slot of each of the plurality of insulation panels, wherein the insertion of the respective upper rib and lower rib (218, 220) at least elastically deforms the longitudinal slot into which they are inserted so as to effectively seal along a length thereof, thereby defining a vapor barrier there between; and - a plurality of splice members, each splice member including a first rib portion and a second rib portion extending in opposite directions from a meeting region there between, the first rib portion and the second rib portion structurally configured to extend into the longitudinal slot of each of the plurality of insulation panels, wherein the insertion of the respective first rib portion and second rib portion at least elastically deforms the longitudinal slot into which they are inserted so as to effectively seal along a length thereof, thereby defining a vapor barrier there between, - wherein, the insulation system is formed by positioning a plurality of bracket members (14, 14') in a spaced apart relationship and extending insulation panels there between, so that the first end wall abuts and overlies the back face of the insulation panel and so that the body wall extends sufficient to have the second end wall abut and overlie the front face of the insulation panel, wherein the upper and lower ribs (218, 220) extend into corresponding ones of the longitudinal slots of the insulation panels, with splice members extending between adjacently abutting ones of the plurality of insulation panels that extend between adjoining ones of the plurality of bracket members. - a plurality of insulation panels, each insulation panel including a front face, a back face and a plurality of side surfaces extending therebetween, the side surfaces including a longitudinal slot extending along at least a portion thereof; - a plurality of bracket members, each bracket member comprising a polymer and including an elongated body having a body wall, a first end wall extending from a first end of the body wall and configured to be attachable to the building substrate and a second end wall extending from the second end of the body wall opposite the first end wall, the body wall having a top surface and a bottom surface, and an upper rib extending upwardly from the top surface of the body wall spaced apart from each of the first end wall and the second end wall, and a lower rib extending downwardly from the bottom surface of the body wall spaced apart from each of the first end wall and the second end wall, each of the upper rib and the lower rib structurally configured to extend into the longitudinal slot of each of the plurality of insulation panels, wherein the insertion of the respective upper rib and lower rib (218, 220) at least elastically deforms the longitudinal slot into which they are inserted so as to effectively seal along a length thereof, thereby defining a vapor barrier there between; and - a plurality of splice members, each splice member including a first rib portion and a second rib portion extending in opposite directions from a meeting region there between, the first rib portion and the second rib portion structurally configured to extend into the longitudinal slot of each of the plurality of insulation panels, wherein the insertion of the respective first rib portion and second rib portion at least elastically deforms the longitudinal slot into which they are inserted so as to effectively seal along a length thereof, thereby defining a vapor barrier there between, - wherein, the insulation system is formed by positioning a plurality of bracket members (14, 14') in a spaced apart relationship and extending insulation panels there between, so that the first end wall abuts and overlies the back face of the insulation panel and so that the body wall extends sufficient to have the second end wall abut and overlie the front face of the insulation panel, wherein the upper and lower ribs (218, 220) extend into corresponding ones of the longitudinal slots of the insulation panels, with splice members extending between adjacently abutting ones of the plurality of insulation panels that extend between adjoining ones of the plurality of bracket members.