The Roof Savings Calculator was developed as an industry-consensus roof savings calculator for commercial and residential buildings using whole-building energy simulations. It is built upon the DOE-2.1E engine for fast energy simulation and integrates AtticSim for advanced modeling of modern attic and cool roofing technologies.

Cool roofs can help many building owners save money while protecting the environment. This guidebook has been created to help explain how cool roofs work, what kinds of cool roof options are available, and how to determine if cool roofing is appropriate for a particular building. Cool roof products exist for virtually every kind of roof.

Why use cool roofs?

Just as wearing light-colored clothing can help keep a person cool on a sunny day, cool roofs use solar-reflective surfaces to maintain lower roof temperatures. Traditional dark roofs can reach temperatures of 150ºF (66ºC) or more in the summer sun. A cool roof under the same conditions could stay more than 50°F (28ºC) cooler. Cool roofs can reduce energy bills by decreasing air conditioning needs, improve indoor thermal comfort for spaces that are not air conditioned, and decrease roof operating temperature, which may extend roof service life.

In many cases, cool roofs cost about the same as non-cool alternatives. The energy cost savings you can realize from a cool roof depends on many factors, including local climate; the amount of insulation in your roof; how your building is used; energy prices; and the type and efficiency of your heating and cooling systems.

Cool roofs can also benefit the environment, and policymakers may issue cool roof regulations to provide these benefits to society. Cool roofs can reduce local air temperatures, which improves air quality and slows smog formation; reduce peak electric power demand, which can help prevent power outages; reduce power plant emissions, including carbon dioxide, sulfur dioxide, nitrous oxides, and mercury, by reducing cooling energy use in buildings; and reduce heat trapped in the atmosphere by reflecting more sunlight back into space, which can slow climate change.