In the 10 years since its launch, the Environments For Living (EFL) program has steadily gained traction among leading home builders across the country, and this year certified its 140,000th home. Initiated by Masco Home Services, the program was one of the first home certifications to base its criteria on building science, relying on early input from Joe Lstiburek of Building Science Corp. and continued focus by its director David Bell, a veteran building scientist himself. “Environments for Living was created from the start to educate builders about building science,” Bell says. “Over the years, by working with companies like Pulte, KB Home, D.R. Horton, Beazer Homes, David Weekley, and Lennar, we’re helping builders differentiate themselves in their markets, and raise the industry’s standards.”

David Weekley Homes, one of many production builders in the program, is building EFL Platinum-level homes in nine markets.
Courtesy David Weekley Homes David Weekley Homes, one of many production builders in the program, is building EFL Platinum-level homes in nine markets.

EFL certification requires builders to meet performance-based criteria to achieve either Gold, Platinum, or, its highest, Certified Green through mandatory measures that ensure a tight air barrier and thermal envelope, right-sized HVAC equipment with properly located and tested duct systems, intentional fresh air ventilation, moisture and water management details, room-by-room pressure balancing, and required installation of carbon monoxide detectors. Certified Green–level homes meet additional requirements for internal water efficiency, including fixtures and plumbing layout, as well as lighting and appliance efficiency criteria. For all EFL homes, the process begins with a plan review to benchmark practices, identify changes, and estimate costs, and continues through construction with visual inspections to view framing, air barrier and thermal envelope integrity, flashing details, and other systems required for certification. And while EFL requirements complement other rating systems like Energy Star, the DOE Builders Challenge, LEED, and the National Green Building Standard (NGBS), programs that many EFL builders also use, EFL does not address site and location considerations contained in LEED and the NGBS.

EFL does require performance testing of all its homes, and after achieving EFL certification, Masco Home Services offers two unique limited guarantees to the original homeowners: a Heating and Cooling Energy Use guarantee that will fully reimburse homeowners for heating and cooling expenses beyond the modeled energy requirements simulated for that home in a typical weather year, and a Comfort guarantee that “... guarantees the original homeowner that the temperature at the location of the thermostat in the home will not vary more than +/- 3 degrees from the temperature at the center of any conditioned room within that thermostat zone.”

For more information on EFL, visit; to learn about Masco Home Services’ WellHome remodeling program, visit