Most of the discussion about the green building movement has centered on the processes, materials and practices used when constructing new, more energy-efficient facilities. Within the commercial roofing industry, much of the attention has been aimed at the return on investment opportunities with photovoltaic and vegetative roofing options, and the debate about white or light-colored reflective roofing materials has focused primarily on TPO, white EPDM and PVC membranes. Insulation also plays a primary role in generating a building's energy savings.
Since gaining industry acceptance during the mid-1970s, millions of square feet of polymer-modified bitumen and built-up roof systems have been installed on commercial, industrial and institutional buildings throughout the U.S.; they, too, should be part of the conversation. Making traditional polymer-modified bitumen roof systems more energy efficient can be accomplished in a number of ways, including reroofing and re-cover options.
There is no question the U.S. Green Building Council's LEED programs have positively influenced the expectations for buildings' energy performance. What you may find surprising is one of the fastest-growing LEED Rating Systems is LEED for Existing Buildings: Operations & Maintenance (EBOM).