As a construction manager in the Atlanta suburbs, in 2007 Luis Imery observed that the indiscriminate tree felling and land moving taking place on job sites didn’t jibe with the green homes, eco-safe cleaning products, and low-emissions vehicles appearing increasingly in magazines and TV programs. A prescient homebuilder like himself could fill that local gap. Yet, rather than pounce on opportunity, Imery planned his entrepreneurial career change deliberately. He and a partner sent questionnaires to Prius and Insight owners, conducted surveys at farmers markets in his Athens, Georgia, hometown and surrounding areas, and held focus groups to confirm the niche.
Photo © Bisig Impact Group
“The conclusion was that a majority of builders were just focusing on curb appeal, while people were legitimately concerned about energy efficiency, water conservation, and recycled content in construction materials,” Imery recalls. “We also found that they would rather live in a community with more mixed product offering, home sizes, and age groups than the average subdivision.”
The slow-and-steady pace not only saved Imery from impulsiveness, but also a Great Recession misfire. As the economy tumbled, he postponed a project launch and continued due diligence. His research turned up Serenbe, a 900-acre sustainable community in metro Atlanta just beginning to take shape; noting that every house in the new neighborhood had to undergo EarthCraft certification. Imery, enamored, decided to become a verifier in that and other green-building standards. Today the Imery Group is rating approximately 200 homes at any given time, in addition to its development portfolio.
When Imery finally did break ground on a house, then, sustainability came effortlessly. Two affordable homes in Athens earned EarthCraft-Platinum ratings, as well as NAHBGreen Awards from the National Association of Home Builders. “In this business model, all the information we gained from the technical advisory services is information we use for potential jobs, and vice versa,” he explains, “the knowledge is kept within.”
With the NAHB awards came an invitation from the online media outlet ProudGreenHome to build a demonstration project—in Serenbe. “That’s when I got interested,” Imery says, “What better place to build a very high-performance home?” With architects Chris and Jodi Laumer-Giddens of Atlanta-based LG Squared, Imery aimed for the 2,800-square-foot spec house to achieve a HERS Index (Home Energy Ratings System) of 0. The net-zero rating would go over and above just another EarthCraft-Platinum certification; in Georgia, the typical new home scores 90 on the HERS Index.
Located on an east-facing lot backed by woods, the Imery Group and LG Squared conceived the residence as a collaboration that made intense use of energy modeling and visualization software. What seems like aesthetic flourishes are actually passive-design improvements: jaunty roof and patio overhangs are calculated according to sun angles; a 29-foot, Boral brick–clad entry volume aids interior convection; stylish concrete floors provide thermal mass; an open floor plan maximizes daylight penetration.
The project team also devoted multitasking thought to the building envelope. Of employing a Huber ZIP System for sheathing the walls and roof, Imery explains that the product, which includes OSB coated in infiltration membrane and padded in foam board, both cuts down on labor while thermally breaking lumber structural members. That structure comprises 4-by-8-foot boards with 2-by-6-inch framing members with 24-inch spacing filled with spray foam, as well as continuous slab edge insulation, to minimize heat loss; a rain screen prevents water penetration.
In a similar vein, decision making was keen to networked inputs and outcomes. In one example, Imery shrouded the building slab in white KleenWrap to capture sheetrock dust and sawdust, a preventive measure that ultimately improves indoor air quality. In another, responding to the envelope’s high R-value and debris-free interior, he layered a standalone ERV on top of a ducted mini-split heat pump system to keep heating and cooling loads in the vicinity of a mere 3 tons.
The house includes energy-producing layers, as well, including a 10-kilowatt rooftop photovoltaic array and solar water heater. Without them, the house scores an impressive 38 in the HERS Index. Factoring them in, the rating plummets to net-positive -2. The distinction is important, because Imery says that removing renewable energy is the simplest way to lower his next residence’s price point and put sustainability within reach of a wider audience.
Whether the next project is just a high performer or swings for the fences depends on the market response to the house at Serenbe. “On the one hand, you have to expose consumers to this new level of sustainability to propel demand for it, but there’s also the risk that the people we already see at tradeshows are just conversing among themselves,” Imery says. In the meantime, the EarthCraft Institute awarded it the 2013 EarthCraft House Project of the Year. Imery will continue raising homeowners’ expectations, via an educational module on ProudGreenHome.com. The real-time case study will include monitoring of every aspect of energy use for one year after the inevitable purchaser’s move-in.