If you’re interested in residential energy efficiency, you’re probably familiar with the marketing pitch of the EPA’s Energy Star Homes program.
Among the program’s claims:
- Energy Star homes “are at least 15% more energy efficient than homes built to the 2004 International Residential Code (IRC), and include additional energy-saving features that typically make them 20 – 30% more efficient than standard homes.”
- “Compared with standard homes, Energy Star qualified homes use substantially less energy for heating, cooling, and water heating — delivering $200 to $400 in annual savings.”
The only trouble with these marketing pitches is they aren’t true. Although several researchers have tried, no one has been able to document energy savings anywhere close to 15%, much less 30%, for Energy Star Homes.
OK, about 7% savings — maybe less
The most recent study to look into the question of whether Energy Star Homes use less energy than baseline homes was a Houston study conducted by Advanced Energy and Michael Blasnik Associates. After comparing the utility bills of thousands of Energy Star homes with thousands of comparable baseline homes, the researchers concluded that the Energy Star homes used 1.9% less electricity and 6.8% less natural gas than the baseline homes. The average Energy Star home in the study had annual energy savings of about $81, not $200 to $400.
As Michael Blasnik said in 2009, when I last reported on the issue, “The Energy Star program started with a low bar. No one has found that Energy Star homes use 25% less energy than other homes.”
A low bar? Well, yes. One of the facts noted in the researchers’ report on the Houston study: “Energy Star homes [in Houston] generally used code-minimum insulation levels.”
Gathering data on over 100,000 homes
A high percentage of new homes built in Houston — about 50% — are enrolled in the Energy Star Homes program. Virtually all of…