What makes a cool roof “cool”?
A whole range of design elements fall under the umbrella term of “cool roofs”. Essentially, a cool roof is one that reflects the suns heat and emits absorbed radiation back into the atmosphere at a higher rate than standard materials, literally staying cooler than a standard roof. This reduces the amount of heat transferred into the building below, keeping it at a more constant temperature.
Cool roofs are one element of passive design which can help keep a building and its occupants comfortable by lessening temperature fluctuations. Incorporating a cool roof into a design in the appropriate climate can make a building “greener” by reducing cooling energy costs, minimise the use or need for installation of air conditioning systems and subsequently reduce utility bills. Cool roofs can also mitigate a community’s Urban Heat Island Effect.