As a result of our efforts to promote cool roofs, the Los Angeles City Council passed a building code update in December 2013 requiring all new and refurbished homes to have cool roofs. A cool roof is made with materials that naturally reflect sunlight; sending solar waves harmlessly back into the atmosphere. While most standard roofs absorb the sun’s radiant energy into the building—transferring it as heat—cool roofs reflect much of the sunlight to keep buildings cooler, increasing comfort and reducing the risk of heat related illness. Typically, a homeowner will see approximately a 10-20% reduction in energy use after installation. Next: We're working to make cool streets mandatory in all densely populated areas, as well as cool playgrounds for schools and parks.