From John McManus at Builder Magazine at http://bit.ly/2yx4RBg “As a measure of value and a behavior changer, RESNET’s scoring and scale benefit owners, buyers, banks, and the planet.” William Thomson was a 19th Century Belfast, Ireland-born child prodigy. He won a prize at age 12 for a Latin to English translation of a satirical classic, Lucian’s Dialogues of the Gods. He was even better at math. He was knighted by Queen Victoria for his engineering work on the transatlantic telegraph, and, Wikipedia notes, “ennobled in 1892 in recognition of his achievements in thermodynamics, and his opposition to Irish Home Rule, becoming Baron Kelvin, of Largs in the County of Ayr. He was the first British scientist to be elevated to the House of Lords.” Absolute temperatures are stated in units of kelvin in his honor, and understanding of the first and second laws of thermodynamics would not be what it is without his work. And, he could turn a phrase, to boot. “When you can measure what you are speaking about, and express it in numbers, you know something about it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarely, in your thoughts advanced to the stage of science.” Why this matters has to do with how you build or remodel, and what kinds of measures come into play that show the value of your work, in real time and over time. One such measure reached a milestone marker in September. The Residential Energy Services Network announced that it had eclipsed 2 million U.S. homes in its Home Energy Rating System scores, which sync up consistent measures of home energy consumption compared with other homes. Last year, more than 206,000 homes received HERS Index Scores, reducing carbon dioxide emissions by over 905,000 tons (which is the equivalent of taking more than 129,000 cars off the road each year) and achieving an annual energy bill savings of $268 million for consumers. In 2012, when documenting the millionth home to receive a HERS Index Score, RESNET partnered with EnergySmart Builder Meritage Home for outreach to consumer media. Using the new 2 million homes milestone to educate consumers, RESNET is also partnering with EnergySmart Builder KB Home on a series of media events on the value of the HERS Index. Now, earlier this month, Rocky Mountain Institute cheered as it announced that realestate.com is working with UtilityScore to provide a score and estimated energy costs for homes listed on its site. Meanwhile Redfin is working with Tendril to provide an Energy Score for all homes on its platform, not just those listed for sale. RMI estimates that 110 million homes are now covered on these two platforms. On our site, RESNET programs director Ryan Meres lauds these initiatives’ intentions, but issues a note of caution in their ultimate effect. He writes: It’s obvious that transparency is a good thing when it leads to competition for improving the energy efficiency of homes. Giving potential home buyers a rough estimate of the energy use of a home provides an excellent platform for incorporating energy use in home buying decisions. However, this doesn’t mean that energy consumption will get factored into the mortgage underwriting or appraisal process; which is the ultimate goal in order to provide value for energy efficiency. Unfortunately, the rough estimates provided by Tendril and UtilityScore are not robust enough for lenders or appraisers to use in their decision making. Interestingly, we instinctively sense that a measure–like miles per gallon, for instance–is a ratio built the way it is because it serves the greatest use in that form. But our instinct and actuality are often not aligned. Here’s a view that shows that while “the job” of the mpg benchmark may be to ensure a measure of value to a car owner, its inverse, gallons per mile, might be a better measure of gas saved. One of the beauties of gpm is that private organizations can take the lead in promoting awareness about the mpg illusion. If Consumer Reports, Edmunds, and car manufacturers started using gpm to express fuel efficiency, the actual value of replacing inefficient cars with more efficient cars would be clear. Car buyers could make better decisions to their own benefit, as well as ours. The point is, the first job of an energy benchmark is to give homeowners and property managers as well as appraisers of value a consistent measure of how a particular home compares with others in its efficiency, performance, and operational costs. The second job is to give residents their own levers to self-manage energy use, and ultimately, cost. This is why we’re with HERS; it’s a measure one can manage to.