A composite fastener, a belly nut, a tie system and/or a method reduce heat transfer through a building envelope. The composite fastener, the belly nut, the tie system and/or the method secure a wall to a backup structure. The composite fastener is constructed from a fiber reinforced polymer that has fibers embedded in a polymeric matrix. The composite fastener has a low thermal conductive value (k-value) and has non-corrosive properties. The belly nut has a fastening hole on a first side of the belly nut to attach the composite fastener to the belly nut. Further, the belly nut has a pathway to receive a leg of a pintle from a top surface of the belly nut to a bottom surface of the belly nut. The pathway is sized to allow for greater vertical adjustment eccentricity between the belly nut and the pintle without creating large horizontal deflections of the tie system.