An insulating system for retrofitting the roof and/or walls of a building. The retrofit system includes a first layer of insulating material extending transverse to the purlins, girts and chords and atop the existing roof or wall structure as well as a plurality of longitudinally extending bridge members each with an upper and a lower surface. The system also includes a plurality of orthogonally extending spacer members that compresses the first layer of insulating material proximate to the spacer members and allowing an otherwise uncompressed first insulation layer to span between the spacer members. The system further includes a second layer of insulation extending across the upper surface of the bridge members wherein a plurality of panel clips each with a panel clip tab are disposed atop the second layer of insulation and are fastened to the bridge member and the clip tabs engage with the lateral edges of the roof or wall panels in the formation of a water resistant seam.