Leadership in Energy and Environmental Design (LEED) is a program under the U.S. Green Building Council (USGBC) to certify “a building or community was designed and built using strategies aimed at improving performance across all the metrics that matter most: energy savings, water efficiency, CO2 emissions reduction, improved indoor environmental quality, and stewardship of resources and sensitivity to their impacts.”
LEED certified builders can have their homes certified as green under the LEED for Homes system, whereby architects specify what sorts of materials and processes will earn LEED certification.
Installing a green roof will get you a half point if it covers over 50% of the home with another point if you install storm water controls to regulate runoff. You can earn a full point for installing a green roof over the entire home and another point when a certified landscape designer or engineer designs an onsite element to handle all the runoff of the home. These credits are under Surface Water Management.
If a your roof improves the overall energy performance of your home, then you may also be eligible for credits under Optimize Energy Performance (EA 1). The points awarded are based on the Home Energy Standards Index that your home achieves when adding up all factors that increase energy efficiency.
When remodeling you can now apply green building practices to your project, and although there is no certification or rating system the resources available through a joint effort by the USGBC and the American Society of Interior Designers (ASID) will help you remodel in a more sustainable fashion. Green roofs help to reduce cooling loads by reflecting some of the heat away. Green roofs also help to reduce the “heat island effect” caused by large areas of dark surfaces absorbing the sun’s heat.
LEED for New Construction and Major Renovations focuses on certification for commercial, institutional and high-rise residential. There are several areas where green roofs add credits under this certification program. In Sustainable Sites green roofs get points for reducing storm water runoff and may also be water treatment devices by the filtration provided through the growing medium. Under the same credit there are other points for mitigating the heat island effect and for maximizing open space. Other credits come into play for Water Efficiency when the green roof is designed without irrigation.
Under the Energy and Atmosphere credit, green roofs earn points for their effect on reducing the building’s heating and cooling loads and making it possible to downsize HVAC equipment. The number of points here is based on the energy reduction levels. Green roofs that improve a workplace, open up educational opportunities or create recreational space also are eligible for credits. These are under the Innovation and Design Process credit.
Manufacturers of green roof systems also highlight specific points related to their systems. In some cases recycled content used in the products qualifies for credit as does regional materials and rapidly renewable materials.
As you move ahead with remodeling, building or buying, you can find advantages beyond certification that make a green roof worth the investment.
Image courtesy of flickr user issyeyre under a CC License.