Walk onto any car lot and you’ll find every vehicle’s fuel economy rating plastered to its window, just like you’ll see a yellow EnergyGuide tag on every large appliance in any department store. Whether for cars or fridges, these tags showcase simple numbers that communicate long-term costs and savings from energy usage. And nowadays, the average consumer considers the impact on his or her pocket (and the planet) that those numbers represent.
Despite the fact that a home can be the biggest financial commitment of a lifetime — and a bigtime energy user to boot — the same doesn’t hold for houses: energy efficiency ratings and related cost savings aren’t stuck to “For Sale” signs or highlighted in all listings. That’s not to say energy efficiency ratings don’t exist for homes — they do — and home building standards have been steadily increasing in energy efficiency. But there is no single, standard, mandated system for rating home energy use, and that may have something to do with why few consumers understand how much evergy costs over time, how to choose energy efficient housing or even how much energy the average home uses — a typical home produces twice the pollution that a car does during the year, and commercial and residential buildings accounted for 12 percent of U.S. CO2 emissions in 2013.
“We don’t really have the vocabulary to speak intelligently about energy efficiency in homes,” says Tim Rehder, senior environmental scientist at the Environmental Protection Agency’s (EPA) Denver regional office. Or maybe the vocabulary is too complicated. For instance, there’s a complex energy scoring system called the Home Energy Rating System, or HERS, designed to be a sort of miles-per-gallon fuel economy rating for homes. But it’s so intricate, Rehder says, that “99 percent of the population still has no idea what a HERS rating means.”
Moreover, HERS is just the measurement — the raw number — that shows energy efficiency. It’s a zero to 150 scale, where 130 is the typical score of an average resale home, a 100 score represents the reference home, a score of 70 is 30 percent more efficient than that, and so on, down to zero — the best score, for a net-zero home that produces as much energy as it consumes. A low HERS score can earn a consumer benefits like an energy-efficient mortgage, and theoretically brings with it lower utility bills for the long term.
Still, folks like Rehder wish HERS could spit out a more understandable score — for example, a simple score expressed in terms like kilowatts of heat energy, or kBtu, per square foot per year, instead of a raw number. Then consumers could more easily develop an understanding of whether, say, 100 kBtu per square foot or 40 kBtu per square foot is efficient or wasteful energy use for their home, in the same way we understand that an MPG rating in the 20s for a mid-sized car isn’t impressive.
Other folks wish HERS could be more flexible and stay in sync with improving technologies. Gene Myers, founder of New Town Builders, is one of the Denver Metro area’s premiere builders of energy-efficient homes and the 2013 winner of the Department of Energy (DOE) Innovation in Housing Award. He laments that HERS scoring isn’t sophisticated enough to capture the high-impact efficiency measures his homes include. The installation of LED lighting throughout a home, for example, far more efficient than compact-fluorescent, isn’t captured in HERS — all forms of efficient lighting are assigned the same value, despite the higher installation costs and greater longterm value. But as a small builder with only a 1.3 percent market penetration in Denver, Myers recognizes that HERS is the yardstick he has to play with. “Our customers are getting incentives based on a HERS score, the mortgage industry knows what HERS is, so you can qualify a home for an energy-efficient mortgage with a HERS score.”
As an ultra-green builder, he’s shooting for a HERS score of zero for his best homes — far beyond ENERGY STAR for Homes standards. (In order to qualify as ENERGY STAR, a home only has to beat the HERS reference score of 100 by 15 percent.) Yet ENERGY STAR is probably the only green brand his consumers recognize, he says, so he carries that label as well. According to the EPA, more than 85 percent of consumers recognize the brand and understand that it symbolizes energy (and cost) savings. The ENERGY STAR for Homes program, part of the program of the same name that rates appliances, harnesses the trust that the brand has built over the years.
The man who helped build that trust as long-time director of ENERGY STAR for Homes, and arguably the biggest influence behind the growth of green building standards in the U.S., Sam Rashkin, is now heading the next generation of an energy efficient home rating program, the DOE’s Zero Energy Ready Homes (ZERH) program. He’s pleased with what ENERGY STAR has accomplished to create greener homes, but ZERH (formerly called the Challenge Homes program) trades the ENERGY STAR “checklist” for a more comprehensive approach, and addresses problematic issues that can arise from simply pushing for a lower HERS score.
“The more efficient a building gets, the more related issues around comfort and indoor air quality and durability have to be managed in parallel,” Rashkin says. A more airtight home enclosure doesn’t leak air, for example, but it also does a poor job of draining moisture, which can lead to structural and human health issues.
It also can’t be fitted with a standard heating and cooling system; “It has to be engineered for comfort by a whole new set of conditions created by that high-performance enclosure.”
“The worst thing we could do is equate the HERS index with green building,” he adds. “It’s simply an energy score. By itself, getting a good HERS score without managing the other risk — it’s a problem for the builder, it’s a problem for the homeowner.”
In other words, simply building more and more efficient homes without improved indoor air quality, protection from water damage and attention to comfort is unacceptable, creating undue risks for builders and home buyers and potentially leading to poorly built — but efficient — homes. The Zero Energy Ready Home label removes that risk, Rashkin says. A ZERH home — including the “Zen” and “Solaris” models by New Town Builders — has an extremely low HERS score, but also a complete water protection system, complete indoor air quality system and an engineered comfort system.
“It’s the future of American housing, here today,” he says. “We’re very effectively moving toward Zero Energy Ready Home as a national marker for zero energy ready performance.”
To prepare the consumer for that market, Rashkin and his team are launching a “Tour of Zero” interactive online database, where visitors can take virtual tours of zero energy homes across the country, see actual utility bills, floorplans and even read quotes from homeowners.
“Essentially Americans can take a tour and see that this is real, that zero energy is real,” he says.
Myers says he already sells 40 to 50 Zero Energy Now (ZEN ) homes a year in Colorado, “which is actually an astonishing number. Before we started you could maybe count the zero-energy homes in the state on one hand,” he says, and there are thousands more in Rashkin’s program nationwide.
“We are getting to a point in time in the life of our country where these things are happening.”
And it’s true: by 2020 every new home in California will have to be a zero energy home, and Rashkin calls home energy standards in Austin, Texas a model already. Boulder’s “green points” system, however, is still based largely on achieving a low HERS score.
But despite the imperfect HERS index and its often-imperfect application, the limitations of ENERGY STAR and the challenge of mainstreaming ZERH, the climate is still benefiting. In Colorado alone there are more than 32,000 ENERGY STAR homes, effectively removing 4,763 metric tons of CO2 from the atmosphere, or avoiding the use of 11,000 barrels of oil. For the people behind the programs, it’s important to recognize that we’re moving in the right direction.
“Ultimately, the ENERGY STAR program is focused on decreasing GHG emissions,” says Kate Gregory, ENERGY STAR coordinator for Denver’s regional EPA office. “That’s the currency that we’re really interested in.”
