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:
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.
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.”
A high percentage of new homes built in Houston — about 50% — are enrolled in the Energy Star Homes program. Virtually all of these homes were certified using the performance method of compliance (using energy modeling), not the prescriptive (BOP) method of compliance.
The Advanced Energy researchers compared the energy used in 106,000 Energy Star homes in Houston to 114,000 “baseline” homes — that is, comparable homes of the same age that were not enrolled in the Energy Star Homes program. The researchers compiled six years of energy consumption data for…