Case Study: Henderson County schoolsBy Margaret Williams on 03/22/2010
At two of Henderson County's newest elementary schools, sunlight makes every room glow, even on a cloudy winter day when the powered lights are off. The abundance of natural light at Mills River and Hillendale — and the many methods used to achieve it — are just a few green features that have earned the schools a Leadership in Energy and Environmental Design (LEED) silver rating (platinum is the highest). From sun tubes to solar panels, from low-flow toilets to sustainable wood, from low-VOC paints to recycled building materials, the two schools are a study in what it means to build green from the ground up and create a better learning environment at the same time.
At Mills River, the green theme started early in the process, beginning with the bricks from the old school, which was more than 100 years old. Instead of being hauled away and likely dumped into the county landfill, the "memorabilia" bricks became part of a fundraiser for the community, says Jes Stafford, construction project manager for the county school system. While the old school — and most of the buildings added to it over the decades — were demolished, those bricks served a useful purpose, says Stafford. And the grounds became a play area for the new school.
Some of the 1970s additions to the old school remain standing, but the block-industrial architecture common during that period contrasts with the new school, which boasts 20 rooftop solar panels, sports an entrance roof that curves upward like the surrounding mountains and marks its halls with color-coded floors that make it easier for new kids to figure out what hall they belong on.
On a December tour, Stafford points to the solar panels, which heat all the hot water used at the school: "That's the bread and butter of our LEED rating," he says. Even on this cold cloudy day, the solar system heats the incoming water supply to a toasty 124 degrees, he explains. In a large room near the solar-paneled roof located at the back of the school, Stafford points out how it all works. Huge water tanks sit in the middle of the room, a series of pipes running in and out of them, connecting them to lines filled with water heated by the energy captured by the solar panels. There's something missing, Stafford mentions: "In an older building, those tanks would have gas burners under them, heating up the water.
"But that's wasteful. You're keeping all the water hot whether you're using it or not," Stafford continues. With Mills River's solar hot-water and heating system — and for a near-identical one at Hillendale — sun energy preheats the water, which is stored in the highly insulated tanks and kept warm until needed. Small but efficient natural-gas boilers make up the temperature difference on demand, he continues, pointing to a row of plain, box-like fixtures. "We don't use all six as you traditionally would," Stafford adds, explaining the process by which only as many boilers operate at a time as necessary and in an alternating sequence that reduces wear and tear on each boiler.
In this way, the system helps heat the school and provides hot water for the kitchen and restrooms.
It's just one of many touches that gained the project points on its way to being LEED-certified.
The process started with an idea presented first to the Henderson School Board and then to County Commissioners: Design and build the new schools with green-building principles in mind at every step, says John Nichols, senior sustainability coordinator for the firm Jim Moseley Architects. With support from the local Sierra Club, designs and technical assistance by Moseley and a little extra funding added by commissioners, both projects were under way by late 2007 and opened in August 2009.
"A number of project requirements — including the schools' solar thermal arrays, tied to high-efficiency, water-source heat pumps — were already envisioned before the decision to pursue LEED certification was made," says Nichols. Facilities Senior Director Bo Caldwell and Stafford, an architect, "were instrumental in their direction on the different technologies and strategies they wanted to see incorporated into the school."
One of those elements is the daylighting design, which includes such features as enlarged windows made with high-performance glass and exterior sunscreens that shade the building interior from most direct sunlight during the cooling season, along with interior light shelves that redirect visible light deep into each room and prevent glare from strong summer light. Reflective ceiling paints further help diffuse the natural light, reducing the need for powered light (and even those are high-efficiency models that are less tiring on the eyes of young students; the lights are also set up to dim when there's sufficient natural light in the room).
Stafford adds that all the classrooms are oriented east to west, which helps get the most benefit from sunlight too: North-facing windows aren't shaded, which allows more light in and helps warm the building walls; south-facing ones have exterior shades that deflect the brightest light of spring and summer.
Green features at the new schools include:
• dual-flush toilets, pint-flush urinals and ultra low-flow lavatories projected to reduced water consumption by 47 percent — about 464,000 gallons per year
• partial ceilings that give the effect of a fully enclosed ceiling but use less material
• between classrooms, full wall structures that reduce noise transfer from room to room, as well as cut down on the noise coming from the HVAC system
• for doors, furniture and such, no particle board and all FSC-certified wood
• low-VOC paints and floor finishes
• building materials from local and regional sources, typically no further than 300 miles away, and the recycling of construction materials onsite whenever possible
• carbon dioxide sensors and outdoor airflow monitors to improve the ventilation of indoor air spaces
• green housekeeping and integrated pest management plans to enhance and protect indoor air quality
And on the metal roof, there are 78 Solatube skylights — large rooftop bubbles that allow light to stream inside through tubes, then temper it through glass fixtures inside that look a bit like a collection of large bug eyes. "That diffuses the light instead of giving you the spotlight effect," says Stafford.
Meanwhile, the kids just know there's work to do, ball games to play at recess and plenty of chances to catch the sun's rays.
Margaret Williams is an editor for Mountain Xpress. She can be reached at or (828) 251-1333, ext 152.