Will Global Warming Rekindle HERS?

Home energy rating programs aren't booming, but they are slowly--very slowly--taking root in both North America and Europe. The birthing process has proven to be much longer and more painful than most people expected. Despite efforts in several countries, these programs have influenced only a tiny, if not insignificant, fraction of home sales. The important thing is that home energy ratings are still around, having survived both falling energy prices and a general dwindling of public interest in energy efficiency.

The collection of articles in this issue about the United States' Home Energy Rating Systems (HERS) program, and its counterparts in other countries, shows that these rating systems are far from dead. And some of the major weaknesses of these systems may be heading toward resolution and improvement.

First, there's movement again toward source-energy accounting, which is actually another way of saying that the ratings are based on energy costs rather than on an unrealistic equating of electrical and fuel energy (see "Gas vs. Electric: An Equal Playing Field at Hand?"). This isn't difficult to accomplish--California has done it for years--but the United States as a whole lacked the political will to accomplish it. Now this country's Kyoto climate change obligations are influencing the debate, because the administration is looking for cheap ways to reduce CO₂ emissions. Also, an influential gas lobby is pushing hard, and a less unified, deregulated electric industry is not resisting as much as in the past.

We have sometimes expressed skepticism about the accuracy of home energy ratings in the pages of Home Energy, but a little experiment performed by Jim Cavallo (see "HERS Experiment Cause for Confidence") has demonstrated that such fears are perhaps overstated. Cavallo asked several raters to rate the same house. He found that, while the ratings differed (although not dramatically), the list of recommended measures--the second half of a good HERS--was very consistant. The experiment needs to be repeated with a larger sample, both theoretically and in actual practice, before we can rely on this conclusion, but it suggests that we might be able to live with a surprising degree of imprecision.

In order for HERS to succeed, consumers must be convinced that the additional cost of a rating is more than offset by the benefits that it brings. Can this happen? An article by Greg Thomas (see "Home Ratings Sweep the Nation--Almost") outlines where that added value will come from. These additional benefits may tip the balance in favor of HERS--if the HERS industry can create the necessary linkages to the contractors, mortgage lenders, utilities, insurance providers, and other institutions who stand to benefit.

As discussed in "European Union not Unified on Home Ratings", the Europeans are also moving toward wider use of energy ratings, but with each country employing a different approach (and achieving a different level of success). Here, too, global-warming obligations are one reason for the widespread push. The U.K. appears to be further along than the United States in rating new houses, but other countries are still trying to devise workable systems. People in Europe also realize that increasing the percentage of energy-efficient homes is one of the cheapest ways to reduce CO₂ emissions.

HERS is a great idea, and its advocates are gradually gathering more strength. Now, with global climate change getting more attention, efficient houses seem particularly sensible.

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