SOM
With In:Posse
And Case

Ground has been broken on what will be the first net-zero public school east of the Mississippi. Situated on a modest L-shaped site in the quiet residential stretches of southern Staten Island, P.S. 62 will offer students and local residents a glimpse of what the architecture of the future may resemble. Designed by SOM in collaboration with sustainability consultancy In:Posse and CASE (Center for Architecture, Science & Ecology, a research and development program operated jointly by SOM and Rensselaer Polytechnic Institute), the project will make use of nearly every arrow in the quiver of sustainability, blending them thoughtfully to create a building that will not only be easy on the environment, but will also be educational.

P.S. 62 is the brainchild of Bruce Barrett, vice president of architecture and engineering at the New York City School Construction Authority. She (yes, Bruce is a woman) had the idea of building a school that would be 50 percent more energy efficient than the minimum required by Local Law 86. The law mandates that projects that receive city money must be built to be 30 percent more efficient than the standards set by ASHRAE 90.1, which itself sets a pretty high bar for efficiency. On top of this ambitious efficiency goal, Barrett also thought that the project should, over the course of the year, produce as much energy as it consumes—thus becoming a net zero energy user.

The net zero standard had its effect on the architectural design. “This is not a formal design exercise,” explained SOM design partner Roger Duffy. “This is really an apparatus, a scientific apparatus that is also attractive, formally speaking.”

To hit its energy efficiency target, the design team, which included lighting design firm Brandston Partnership, focused on establishing ideal solar orientation, maximizing daylight on the interior and creating a tightly sealed envelope. The two-story, 66,000-square-foot building’s rectangular plan faces its narrower walls roughly north and south, while the long walls face east and west. The team restricted glazing to 30 percent of the envelope. On the south face—which receives the most sun—the fenestration is expressed in two horizontal strips for each of the two floors, an upper clerestory window and a lower vision window. The windows are operable, well shaded by overhanging eaves, and treated with light diffusing material to reduce glare. The north side features traditional punch windows. Elsewhere in the project, indirect daylight is transmitted via skylights through double-height atriums and interior windows to illuminate as much of the interior as possible. Through these measures daylight provides 90 percent of necessary light to the south side spaces, 60 percent to the north, and between 50 percent and 75 percent to the interstitial spaces, such as the cafeteria and gymnasium.

The building envelope itself is a high-performance, precast concrete rain screen system. In order to provide the tightest seal possible, the precast panels, which feature an irregularly undulating pattern that breaks up the building’s mass, span from the foundation to the roof, a distance of some 60 feet, without any intermediate connection to the structure. This move avoided the necessity for penetrations through the building’s insulation and vapor barrier thus providing as airtight a building enclosure as possible.

Most of the energy generated on site will come from a photovoltaic (PV) panel-wrapper that rises up across the south facade and covers the roof. Researchers at CASE conducted an efficiency study to determine the best profile for the wrapper as well as the optimal angle for the PV panels themselves. They determined that a combination of flat panels and panels sloped between 20 degrees and 40 degrees would produce the optimal amount of electricity for the site. They also determined that they could maximize the number of panels that the roof could accommodate by combining sloped and flat surfaces, as opposed to a single slope. The resulting design takes these considerations into account as well as the mandates of local zoning regulations and height restrictions.

The exact amount of energy that the PV array will produce is not yet known. The technology of PV panels is evolving rapidly. As a result, the designers decided to delay procurement until the moment when the panels will be required for construction. They estimate, however that over the course of one year, the PV array will produce approximately 1.9 million kBtu of energy, enough to offset the anticipated energy use of the building.

A stellar example of sustainable design, P.S. 62 will actively educate its users about how the way they use the building affects its energy consumption. A system of interactive displays placed throughout the building will supply real-time data about energy use and energy production. So if a student turns on or off a light, or opens or closes a window, the consequences of those actions on the consumption of electricity will be made absolutely clear.