Thursday, January 3, 2013

Ground Broken on Staten Island for First Net-Zero School

Ground has been broken on what will be the first net-zero public school east of the Mississippi. Situated in the quiet residential stretches of southern Staten Island, P.S. 62 will offer students and local residents a glimpse of what the future may resemble. The project was designed by Skidmore, Owings & Merrill in collaboration with C.A.S.E.- a research and development program operated by Rensselaer Polytechnic Institute. The project will make use of nearly every method of sustainable construction to create a building that will be easy on the environment, as well as educational.

P.S. 62 is the brainchild of Ms. Bruce Barrett, vice president of architecture and engineering at the New York City School Construction Authority.

She had the idea of building a school that would be 50% more energy efficient than the minimum required by NYC's Local Law 86.

The law mandates that projects that receive city money must be built to be 30% more efficient than the current national standards, which sets a 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.

To hit its energy efficiency target, the design team, this 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 building exterior.

On the south face, which receives the most sun, windows are aligned in two horizontal strips for each of the two floors, an upper ventilation 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 atrium's and windows to illuminate as much of the interior as possible. Through these measures, daylight provides 90% of necessary light to the south side spaces, 60% to the north, and between 50 and 75% to the cafeteria and gymnasium.

The building itself is a high-performance, precast concrete rain screen. In order to provide the tightest seal possible, the undulating concrete panels, 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 panel system that rises up across the south facade and covers the roof. Researchers at Center for Architecture, Science; Ecology conducted an efficiency study to determine the best profile 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 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.