Light-colored roofs made of vinyl are an extremely popular, cost effective, energy-saving alternative to traditional dark-colored roofs on commercial buildings.

How it works:

On a 90° F day, the temperature on a black roof can be as high as 160° F, according to The Heat Island Group at the University of California, Berkeley. Some of that heat is transferred inside to the occupants of the building, resulting in higher utility costs for air conditioning to keep the occupants comfortable.

Light-colored vinyl roofing membranes reduce this problem by reflecting sunlight, bringing temperatures six to eight degrees lower.

According to the California Energy Commission (CEC), cooler roofs reduce peak electricity demand for cooling, improve building comfort, reduce the "heat island" effect and even reduce air pollution. Of course these energy savings also result in cost savings for the consumer or the taxpayer.

Studies by the U.S. Environmental Protection Agency (EPA) and the Florida Solar Energy Center further confirm that reflective roofs made of vinyl membranes or other single-ply materials can reduce utility costs of air-conditioning by as much as 50 percent.

The Proof:

With more than 30 years of documented performance, vinyl roofing membranes have proven to be as structurally sound as other materials, designed to resist wind uplift, structural movement and harsh outdoor elements. An additional benefit: vinyl roofing membranes generally have good fire performance because of the fire-retardant nature of pure vinyl and the addition of flame retardants. Moreover, a draft report from the U.S. Green Building Council's (USGBC) PVC Task Group found that the environmental and health impacts of vinyl building products are comparable to, and could be lower than, those of products made of competing materials.

Vinyl roofing membranes can also be found as a component in urban "green roofs," which consist of a multi-layer soil and drainage system upon which vegetation can grow. Green roofs, in turn, improve the energy efficiency of buildings, enhance the look of urban rooftops and promote healthier air in such areas.

"Available evidence shows that vinyl products can contribute to the environmental performance of sustainable buildings," Vinyl Institute President Tim Burns said. "Whether it is the energy savings provided by vinyl windows or the resource conservation of durable products like pipe, siding and flooring, vinyl has a place in 'green' buildings."

Case Study: San Marcos Unified School District, Calif.

Jim Poltl, director of maintenance and operations for the San Marcos Unified School District in San Marcos, Calif., has installed reflective vinyl roofs on several projects and is now covering 30,000 square feet at three school sites with these roofs.

"This is an excellent design and a good system," he said. His district of about 12,000 pupils started the retrofitting project because the old roofs on single-story manufactured classrooms were leaking. However, once the new system was installed -- complete with improved insulation -- he started hearing comments from teachers who noticed how much cooler and quieter their rooms were. "The money saved on energy costs is really the icing on the cake," Poltl said.

Case Study: University of California, Los Angeles

Greg Zoll, senior superintendent at the University of California, Los Angeles, has also employed several white vinyl membranes on campus rooftops throughout the last five years. He noted that they typically save 20-30 percent in energy costs, with building occupants reporting cooler temperatures that allow them to reduce the energy and costs spent on air conditioning.

"These roofing systems are designed to last 30 years, so multiply that out over the roof’s lifecycle for the true savings,” Zoll said. During peak air-conditioning season, he figures the University saves an average of $800 a month on each of these buildings, or about $10,000 a year in energy costs. “It’s common sense to do this.”