If you’ve been in the Issaquah Highlands on the first Thursday of the month this summer, you may have noticed small crowds gathering near a construction site on NE High Street. The mixed groups of real estate agents, residents and reporters all have one thing in common; they want to learn more about the zHome.

The zHome has been touted as the first multi-family, zero-energy community in the U.S. In addition to using zero net energy, the homes are expected to use 60 percent less water and create no net carbon emissions. When construction is completed in spring of 2011, the neighborhood will have 10 townhome units.

With the wide-range of innovative components in the zHome, many questions arise about the function, feasibility, maintenance and use of these technologies. To address these inquiries, and to educate citizens about the project, the City of Issaquah is hosting monthly tours of the site.

“The zHome project has always been about education, as much as market transformation,” said City of Issaquah zHome Project Manager Brad Liljequist. “Since the very beginning, the education component was a big part of the idea.”

In addition to the local tours, over the past year Liljequist and the zHome team have spoken more than 2,000 architects, builders, students and sustainability experts about what will make the zHome tick, and what lessons are being learned about the expansion of zero energy construction projects in the future.

The most recent tour on Aug. 5 introduced the dozen or so attendees to the intricacies of geothermal heat pumps. The system being used in the zHome project transfers warmth stored by the earth into the residence, for heating. The heat pumps use electricity only to circulate heat, not create it, which makes them extremely efficient, transferring four to five kilowatts of heat for every kilowatt of electricity used.

When a tour visitor asked whether the system would be efficient enough to sell excess energy back to power companies, Liljequist responded that the meter would run backwards during the day to create the surplus energy that will then be utilized during the night.

As construction on the townhomes progresses, monthly tours will discuss other sustainable elements of zHome, including solar panels, a rainwater catch system, pervious pavement and low-impact stormwater filtration.

The next tour is scheduled for 3:30 p.m., Sept. 2. For more information on the project, visit www.z-home.org.