Marin Country Day School
Stepping Up to Zero Energy: With the second phase of its campus plan, a private school on an idyllic site aims for net-zero.
Students at Marin Country Day School measure academic progress with their school’s topography. Located in a sharply sloping watershed that descends Ring Mountain to San Francisco Bay just north of the Golden Gate Bridge, the 35-acre campus is organized with the lower school at the lowest elevation and the upper school at the highest. Every academic year concludes with a graduation ceremony, called “Step Up,” during which rows of students sit on a terraced concrete grandstand set into the hillside. One by one, each class is asked to literally step up to a higher tier to signify the students’ advancement to the next grade.
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Since its 1956 founding, the private school has treated its connection to the topography and ecosystem of its site as a point of pride and an academic focus. In recent decades, the school—where tuition for a sixth grader can top $25,000 per year—has used that connection, along with complementary emphases on technology and social justice, to attract the affluent, progressive-minded families who call the Bay Area home.
When the school decided to update many of its wood-shingled, cabin-like buildings, the board and planning committee wanted the new structures to edify the place of environmental learning in its curriculum and philosophy. “We have incorporated environmental sustainability into our program and teaching practices for a long time,” says head of schools Lucinda Lee Katz. “But the new buildings allow us to walk our talk.”
The school called on San Francisco-based EHDD Architecture to transform the campus. Begun in 2007, the firm’s multiphase master plan included six new buildings—33,000 square feet of new construction—and a series of renovations. The plan set out to not only meet the school’s basic pedagogical needs for collaborative teaching spaces and contemporary technology, but it sought to preserve the rough-and-ready feel of the existing buildings, open up new sight lines to the surrounding mountains, and crucially, according to the school’s board, refrain from expanding its existing footprint. The project team aimed to deliver all of this, while rehabilitating the surrounding watershed and enabling the new buildings in the latest stage of the project to produce more energy than they consume.
The school completed the LEED Gold-certified first phase of the plan in 2008. The larger, $12.8-million second phase, including a new library, art studios, and classrooms, was finished in late 2009, and its newly built structures were certified Platinum under LEED for Schools in May.
The centerpiece of Phase Two is also Marin Country Day’s most ambitious new building. EHDD designed the Learning Resources Center (LRC)—a 13,600-square-foot building primarily housing the library, a technology classroom, and student services—with the goal of reaching net-zero energy. The main entry, on the west elevation of the two-story structure, encloses an atrium, stairs, and an art gallery behind a glazed facade. Low-emissivity glass and deep louvers prevent solar heat gain, while allowing natural light in and views out to the landscape. Rows of operable windows illuminate the library and classroom spaces. Along the center of the second floor, a solar chimney lined with light shelves provides more daylighting and facilitates stack-effect cooling.
In addition to natural ventilation, the building maintains its interior temperature using graywater. A catchment system draws rainwater down to a 15,000-gallon cistern buried below grade, where subterranean temperatures keep it cool. Water is then pumped back into the building where it alternately travels the pipes of an in-floor radiant cooling system or is diverted for toilet flushing. The system uses roughly 10 percent of the energy of a traditional compressor, according to Scott Shell, AIA, a principal at EHDD and the firm’s sustainability director. On the roof, an evaporative cooling tower supplements the radiant system and passive ventilation.
Designed to account for the entirety of the building’s energy use as well as that of the other new structures completed in the second phase of the project, a 95.5–kilowatt photovoltaic array lines the long, uninterrupted south-facing roofs of neighboring classroom buildings. “We kept pushing for the array, and the financial types on the board finally decided that they had the money in the endowment to buy it outright as an investment strategy,” says Shell. “What I think people don’t always understand is, yes, photovoltaics are expensive, but for this building they only account for 1.5 percent of the construction cost, which seems much more manageable.”
The LRC sits on the north side of the “Step Up” court, opposite its concrete bleachers. On the east side of the courtyard, the firm replaced a set of existing art classrooms with a series of five, two-story structures—also designed to be net-zero energy buildings—housing new art studios on the ground floor and classrooms above. An elevated, open-air hallway runs along the second floor, connecting the new structures to the library as well as to a group of renovated existing upper-school classrooms set higher on the slope.
A seasonal creek forms the eastern boundary of the campus. EHDD reconnected the waterway, once walled-off by now-demolished buildings, to the campus by adding a break in the row of new structures. The gap opens the “Step Up” court to the creek and creates small gathering places in the interstitial space.
EHDD also restored the creek to a more organic state. The team removed a concrete channel and widened the bed, lowering the peak water level by about one to two feet. The firm also added a series of pools along the water’s course to further slow its progress to the bay and prevent erosion.
Seventh-grade science classes monitor creek levels and water quality in one of the many ways the project’s sustainability initiatives have entered the curricula. The school is currently installing a digital energy-monitoring system to use as a teaching tool, allowing students to test actual energy consumption against the net-zero goal and help make any necessary adjustments. “The whole concept of monitoring the LRC to see if it does in fact generate more energy than it consumes has taken us to the next stage of consciousness,” says Katz.” And it has enabled the kids to participate in the process.”
William Hanley is a Brooklyn-based journalist. He is GreenSource’s Web editor.