Assorted Signals from the Green Building Market

Homebuyers and builders wrestle with perceptions about costs and benefits of energy efficient homes; meanwhile, a notable increase in the number of certified Passive House consultants suggests the standard will gain a firmer foothold in the U.S.

Posted on Nov 17 2010 by Richard Defendorf

There currently are about 200 certified Passive House consultants in the U.S. An updated version of this interactive map can be accessed on the Passive House Institute US website.

Even if they are not entirely clear about its potential benefits or what it should cost, more consumers than ever seem to think green building is a good idea. That’s one of the broad conclusions of two National Association of Home Builders Research Center surveys conducted for Habitat for Humanity and Whirlpool Corporation. One survey, conducted in August, queried consumers; the other, conducted in July and August, focused on builders.

More specifically, the majority of consumers surveyed agreed that a green home would be affordable to live in and maintain. The respondents supporting that view came from three income categories: high (67%), upper-middle (65%), and middle (59%). Among low-income respondents, 48% agreed with that perspective. One of the key takeaways in the survey, though, is that only the high-income respondents – 71% of those questioned – agreed that a completely green home would be affordable to purchase.

So there is a disconnect, as the researchers put it, between what most consumers believe a green home can offer and their perception of whether or not it is affordable. Among the builders surveyed – all of whom are members of the NAHBNational Association of Home Builders, which awards a Model Green Home Certification. Research Center’s Online Builder Panel – 87% indicated they believe green homes are affordable for middle-income families to live in, while 30% felt green homes were too expensive for that segment to purchase or build. For low-income families, 70% of homebuilders believe green homes are affordable to live in, while almost 60% thought green homes were too expensive for that segment to purchase or build.

In a press release summarizing the survey results, however, Habitat for Humanity emphasizes that it has introduced a relatively high level of energy efficiency performance into many of its projects, all of which must meet relatively stringent standards of affordability. The release also includes a comment from Larry Gluth, senior vice president of U.S. and Canada for Habitat for Humanity International, intended to drive home the point. "Under Habitat's nonprofit construction model,” he notes, “Habitat affiliates across the United States are incorporating sustainable materials and energy-efficient products in Habitat homes, as this is both a responsible building practice and it improves the affordability of homes for Habitat partner homeowners.”

Passive HouseA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. expertise spreads
If the NAHB surveys highlight challenges in bringing more clarity to perceptions about green building and its costs and potential benefits, a brief posted this week by Architectural Record magazine offered an encouraging perspective on professional interest in the Passive House performance standard.

The Record item, pegged to the 5th North American Passive House Conference held earlier this month in Portland, Oregon, includes a short Passive House backgrounder, but also points to increased interest in the standard among builders, architects, designers, and energy efficiency specialists. For example, the conference, which drew only a few people to its inaugural meeting, attracted about 350 to the event in Portland. Just as important, Mike Kernagis, program director for Passive House Institute US, told the magazine that the number of certified Passive House consultants went from 15 in 2008 to 200 in 2010.

“This is the first conference,” he said, “where we’ve really reaped the benefits of having the consultants come back and show their first projects.”

Also well represented at the conference: Habitat for Humanity, whose representatives highlighted the group’s Passive House projects in Vermont, Kentucky, and Washington, D.C.