Since states began adopting energy codes in the 1980s, newer versions of the energy code continue to be adopted every few years, with each new version ratcheting up the stringency of energy requirements. As each new version of the code is debated, code advocates argue that the latest version of the code will save energy compared to earlier versions.
Now that we are several decades into the energy code era, it’s probably time to ask the question: Are energy codes saving any energy? That’s precisely the question that David Baylon set out to answer—specifically for commercial buildings in Oregon and Washington. Baylon is the founder of Ecotope, a consulting firm in Seattle that specializes in energy conservation.
Baylon gave a presentation on the topic at last August’s Westford Symposium on Building Science in Massachusetts. He started his presentation with a brief history of building energy codes in the U.S., after which he then said, “Did we make progress? The short answer is, ‘Well, not exactly…’”
Baylon narrowed his focus by looking at commercial buildings, in part because he had access to four giant datasets that provide utility billing information on hundreds of commercial buildings. The key metric that Baylon used for comparison—what he called “the figure of merit”—is Energy Use Intensity, or EUI. This is defined as the annual energy use per square foot of building, and is expressed in thousands of Btu per square foot. EUI includes electricity use (for all purposes) as well as all other forms of site energy, including any natural gas or heating oil burned on-site.
These were the datasets Baylon looked at:
Taken together, these datasets included utility billing information spanning over 30 years. Baylon decided to focus on three categories of commercial buildings in these datasets:…