Cool Roofs for Energy Efficient Homes

Energy costs for cooling your home with an air conditioner can be very expensive. A ‘cool roof’ is an important step towards reducing utility bills while extending the life of your roofing material in your green home.

‘Cool’ or ‘cold’ roof installations function by allowing heat that is built up from absorbing the sun’s energy to escape via convection prior to it passing through the structure and insulating portion of the roof of the home. This is typically achieved by adding strapping run with the slope of the roof over the main roof structure, then applying the roof material of choice (sometimes over another layer of roof sheathing) while venting the air cavities at both the eave and the ridge. While the roof absorbs and transfers heat during the day, it warms the air within the cavities and natural convection draws cool air in at the eave while the heated air disperses at the ridge.

Roof material color selection also plays an important role; lighter colors will reflect more heat preventing heat buildup while the darker colors (reds, blacks and greens) will absorb more heat.

Long-term benefits include significantly reduced energy bills, increased comfort, the ability to reduce the size of, or possibly omit, air conditioning units in the home, less roof maintenance, and an extended roof life resulting in less waste. Some states, such as Arizona, California, Florida, Idaho, Texas, and the Carolinas offer rebate programs for cool roof installations.

Bonin Architects & Associates can help you choose the best cool roof materials for your energy efficient home based on where you live and the design of the home.

Jeremy Bonin, AIA NCARB LEED AP
Bonin Architects & Associates, PLLC