Editor’s note: This is an abridged version of an article that originally appeared on the Kendeda Fund’s Living Building Chronicle blog. The original post can be found here.
A Virginia school’s recognition last month for its net zero energy status is part of a growing trend in the Southeast.
According to the New Buildings Institute, four of the five states with the most net zero energy schools underway in 2016 were in the South — despite low power rates and few policy incentives.
Ground zero for net zero schools is, of all places, coal-rich Kentucky, where then-Gov. Steve Beshear tapped federal stimulus money to offer incentives for schools to become more energy efficient.
In South Carolina, there’s a county system planning five net zero facilities. A North Carolina district has committed to building only net zero from now on.
And in Virginia, Arlington Public Schools is operating one of the nation’s largest net zero buildings of any kind.
“Net zero wasn’t even part of the [Arlington Schools] proposal,” Discovery Elementary School architect Wyck Knox said before collecting an award at last month’s U.S. Green Building Council’s Green Schools Conference in Atlanta. “We looked at it, and said, ‘You know, we think that we can do this at net zero energy and still stay under-budget.’”
It helped that Knox, who practices at VMDO in Charlottesville, Virginia, was pitching his ambition to a system with a strong sustainability track record. At least five of Arlington’s schools have achieved LEED certification.
In its bid for the 98,000-square-foot project, VMDO presented Arlington with a choice. Either contract for a “net zero ready” building for $30.7 million, or contract for the same building but spend another $1.3 million on nearly 500 kilowatts worth of solar panels. As it turned out, both bids were well below the system’s $36 million budget.
“We didn’t make a big deal about it,” says John Chadwick, assistant superintendent for facilities and operations. “We didn’t even present [the net zero potential] to the board. It just ended up flying in under the radar.”
Turning a corner
Net zero energy can mean slightly different things to different people. Generally, a building meets the definition if, through a combination of efficiency and onsite renewable energy, it produces as much energy over the course of a year as it uses. If it produces more clean energy than it uses, it’s net positive.
In 2016, the feasibility of net zero K-12 schools seemed to turn a corner. The New Buildings Institute’s list of “verified” and “emerging” net zero buildings reached 332 projects in November — an increase by three-quarters over 12 months. Thirty-eight percent of those buildings were K-12 schools.
“We used to have arguments about whether it was technically feasible,” says NBI’s Amy Cortese. “That conversation is over.”
Cortese is careful to note that net zero (which NBI refers to as “zero net energy”) isn’t a slam dunk for more energy-intensive building types, such as hospitals. But schools — particularly elementary and middle schools — are a good fit for a number of reasons. They have predictable and relatively constant energy demand, they have large roofs suitable for solar panels, and districts have a long-term interest in reducing energy costs and possess bonding authority for big projects.
A building’s sustainable features can also offer up a teachable model for both the environment and technology. The most creative design teams draw out those themes by employing nature-based motifs and by engaging students with energy dashboards and observable systems.
“In many circumstances, [net zero] can be done for the same cost as a conventional building, and once they’re in place, they save every year on utility costs,” Cortese says.
The rules are changing
Once a project is approved, net zero designers typically follow a rule of thumb: Before sizing renewables, they do everything possible to cut their projected energy demand. Or as Reilly Loveland (a colleague of Cortese at the New Buildings Institute) puts it: “You have to eat your efficiency vegetables before you move on to the cake.”
Discovery School’s designers studied the building’s orientation and massing to maximize passive solar. They created a tight envelope by using insulating concrete forms and, Knox says, through “an obsessive attention to detail.” They did a lot of energy modeling. They followed CMTA’s recommendation to heat and cool the building with 58 geothermal heat pumps, which effectively broke the school down into sensor-controlled zones — each serving about two classrooms.
At the same time, solar’s plummeting costs and improving efficiency have begun to disrupt the vegetables-before-cake menu. Knox describes one example: When he learned it would take $119,000 to upgrade all of Discovery’s windows from two panes to three panes, he asked CMTA what it would cost to up-size the solar to adjust for sticking with double-pane windows. The answer: $9,000.
“Adding the panels was a no-brainer,” Knox says. Still, he advises, “95 percent of the time, conservation’s going to be the way to go.”
Lessons learned
The ultimate “customers” for any school are, of course, its students. Knox was acutely aware of that fact as he and his team designed Discovery Elementary. As a result, environmental awareness is reinforced throughout the building. Each grade’s classrooms are built around a common hallway with a way-finding motif built on broader and broader realms of nature. Kindergartners are “Backyard Adventurers.” First graders are “Forest Trailblazers.” And so on, all the up to fifth grade “Galaxy Explorers.”
There’s also a very active Eco-Action Team. At the front entrance, a spiffy, modern solar calendar tracks seasons. There’s even a Solar Lab, where students are able to interact with the school’s rooftop electric and water systems. Making the building’s systems transparent went hand-in-hand with putting sustainability front and center.
CMTA’s Devin Cheek is particularly proud of the school’s energy dashboard. After an off-the-shelf product crashed, he and his team devised a custom dashboard that tracks the energy production, energy consumption and the net of those two numbers. In addition to accessing it real-time from any computer, students can view the dashboard on a large-screen TV in the entrance lobby and on a waterproof version in the rooftop solar lab.
It helps that the dashboard consistently shows good news. Discovery’s performance since it opened in Fall 2015 has exceeded expectations. This school year, both Knox and Cheek have taken to looking gleefully at the dashboard and proclaiming — with guarded optimism — that Discovery’s 2016-17 school year could “blow net zero out of the water.” Even the winter months ran net positive. This year, the school is expected to save the district some $80,000 in power bills (compared to the typical Arlington elementary), and that number is likely only to get better.
Similar stories at other net zero schools appear to be building momentum for the net zero movement. Knox points to net zero projects popping up in Maryland that are looking to the nearby Discovery Elementary for inspiration.
Similarly inspired by a net positive school in Sandy Grove Middle School in Lumber Bridge, North Carolina, the Horry County, South Carolina school board committed last year to five net positive projects: three new middle schools, an intermediate school and an elementary school. The smallest of those five schools — which were designed by SFL+A of Raleigh, and are scheduled for completion this summer — will be 120,000 square feet.
For Chadwick, the progress is tantalizing. Those spanking new net zero buildings are one thing, but he notes that most schools were built years ago.
“It’s much easier to do this on a new building,” says the sustainably minded facilities chief. “The next frontier is how we can do it on an existing building.”