Mastic Home Exteriors by Ply Gem. Structure EPS insulated vinyl siding can boost a wall’s R-value by 25% and help cut down on exterior noise. Now the material comes in longer 16-foot- 8-inch lengths for quicker installation and fewer seams. Available 7-inch, double 6-inch, and double 4½ -inch Dutch lap panels are backed with up to 1¼ inches of polystyrene insulation. Beginning in 2011, insulated siding meets requirements of the Energy Star Qualified Homes program. 800.962.6973.