Building Codes
Study Suggests Building Codes Can Cut Energy Use—at a Price
Max Taves
May 18, 2014
How big a role can building codes play in reducing energy waste?
That's the question economists Grant Jacobsen of the University of Oregon and Matthew Kotchen of Yale University sought to answer by comparing monthly electricity and natural-gas bills of 2,200 Gainesville, Fla., homes built three years before and three years after Florida tightened its home-building code in 2002. The state made the change to bring its code in line with the International Energy Conservation Code—a model for setting minimum energy-efficiency standards for new and remodeled buildings. The code is in use in 46 states, though local and state governments enforce it in widely varying degrees.
According to Messrs. Jacobsen and Kotchen, homes built after the change consumed, on average, 4% less electricity and 6% less natural gas—savings that homeowners achieved in a variety of ways, including using less-leaky air ducts, more-heat-resistant windows, better insulated attics and certain white roofing products.
The Wall Street Journal discussed the findings with Mr. Jacobsen.
WSJ: Broadly speaking, what did you find?
MR. JACOBSEN: More stringent energy codes are effective at saving more energy.
WSJ: What did Florida require of new homeowners to meet the stricter code?
MR. JACOBSEN: Their codes don't place any direct restrictions on homeowners. Rather, in order to get a building permit, a new residence's overall design features had to meet a certain number of points, which are assigned for their efficiency.
WSJ: How much did the tighter standards raise costs?
MR. JACOBSEN: We aren't able to precisely measure, but it's likely that the increase in cost was less than $1,000. We estimate that homeowners would recoup those extra expenses in about seven years based on the estimated energy savings we found.
WSJ: One argument against building-efficiency changes is the rebound effect—that is, people use more energy now that it's cheaper, nullifying the intended effects of the changes. Did your study find a rebound?
MR. JACOBSEN: We did not find any evidence that the rebound effect occurred at a level that was significant enough to substantially erode the projected energy savings.
WSJ: Are the changes that you found—the 4% drop in electricity and the 6% drop in natural gas—big savings? Did you expect to see more?
MR. JACOBSEN: The findings are consistent with what we expected based on energy simulations. Larger increases in stringency would likely lead to larger savings.
WSJ: How do these savings compare with other ways of encouraging savings, such as rebate programs or the OPower Inc. approach of using software and behavioral science to get utility customers to use less energy?
MR. JACOBSEN: Overall, the energy savings from a policy are going to depend on a lot of details, so it's difficult to make general comparisons. All policies have some limitations. OPower, for example, is going to be limited to some extent because it relies on voluntary behavior.
Rebate programs provide a financial incentive to invest in energy efficiency, but research shows that consumers often overlook energy-efficiency investments even when they're financially sensible. Energy codes have the benefit of being mandatory, but are limited because they only apply to new buildings.
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SOURCE: online.wsj.com