Campbell Crossing in Fort Campbell, Ky., is a community of new, traditionally styled, modestly priced duplexes that hark back to older neighborhoods with walkable streets and easy interaction among families.
Except that the homes in Campbell Crossing are far more energy- and resource-efficient than anything an older home (including most of those built earlier this decade) could muster—and, for one of the duplexes, that only a relative few new homes, and even fewer in the same price range, can match.
The duplex, comprising two, 2,000-square-foot, two-level homes, was designed and built to achieve net-zero electrical use, originally to give Actus Lend Lease, the project’s developer, builder, and property manager, a better sense of the coordination required and costs associated with meeting that standard.
“Initially it was an opportunity for us to better understand how and where we can build zero-energy homes within a production-built environment,” says Mark Sierra, managing director of the Nashville, Tenn.–based company, which works exclusively within the Defense Department’s Military Housing Privatization Initiative. “Campbell Crossing brings together everything we’ve employed on other projects,” in terms of products and practices that enhance environmental performance.
That includes the company’s groundbreaking use of solar energy on military housing in 2004 and improvements in building envelope design and construction a year later that nearly doubled the shell’s R-value and significantly reduced air infiltration and overall energy demand.
The zero-energy duplex in Campbell Crossing features both, as well as passive solar design, geothermal heating and cooling systems, controlled heat recovery ventilation, and energy- and water-saving fixtures and appliances—many of which are also standard specs for the rest of the homes the company will build there. The project also enlightened Actus Lend Lease about the process of achieving net-zero energy use, a “next step” that the company found required a higher level of coordination and commitment among its trade partners and suppliers. “It’s extremely important to have an integrated design process and interaction among all interested parties, including the homeowners,” says Patrick Tahaney, development manager at Campbell Crossing for Actus Lend Lease.
That commitment extends from whole-house energy modeling and bid documents stating the project’s zero-energy goals to hosting preconstruction meetings with subs to ensure they help instead of hinder each other to make it happen. “It’s critical that everyone get involved early,” Tahaney says.
Completed and occupied in October, the zero-energy duplex is expected to consume less than half of the energy of a home built to the 2009 international energy code; reduce water heating and air-conditioning energy use by 78 percent and 70 percent, respectively; and cut hot water use by 7,300 gallons, among other efficiencies.
But expectations aren’t enough. If phase 1 of the experiment was to learn how to build a zero-energy home, and at what cost, phase 2 is proving it in the real world of homeowners and their everyday lifestyle habits.
To that end, monitoring systems and in-home displays will track the energy and resource performance of the net-zero duplex and that of a neighboring “baseline” home for 12 months, allowing Actus Lend Lease (and various partners) to gauge the impact of—and possibly alter—occupant behavior as it relates to optimizing the homes’ built-in efficiencies.
“We hope to answer some very important questions about how [resource-efficient] systems integrate and perform over time once the house is occupied,” says Tahaney. “Will the residents appreciate and place value on those features? The answers we get will shape the future of zero-energy homes across the country.”