This undulating roof serves as an arresting crown for a heating plant, proclaiming the project’s preeminent greenness and contributing to its LEED certification. The design accomplishes divergent goals: it makes infrastructure alluring by creating an iconic presence on this independent school campus; while the low-slung structure, whose vegetated roof is the color of surrounding flora, melds with its bucolic environs.
Designed by Centerbrook Architects of Essex, CT, USA, the16,500-square-foot plant provides heat for 600 students and faculty and 85 buildings, but there were other project objectives: reduce greenhouse gas emissions to help the school become carbon neutral by 2020; lower utility costs with a local sustainable fuel, in place of foreign oil; do double-duty as a classroom by exposing green systems and materials to close observation and study. Sustainably harvested woodchips, an IPCC-designated renewable fuel, replace 150,000 gallons of imported fuel oil annually, cutting emissions, most dramatically sulfur dioxide by 90 percent. Waste ash is collected for use as fertilizer on student-tended gardens. During the first winter, the school reported substantial savings in heating costs.
Supporting the roof are glue-laminated timber trusses, a manufactured wood product that optimizes the structural values of this renewable resource. Glulam has less embodied energy than reinforced concrete or steel and can be used for longer spans, heavier loads, and complex shapes. Other local and renewable wood products were used throughout for framing, railings, veneer, and composite wallboards.
To make the building an ancillary classroom a specially designed mezzanine affords views of plant operations and also houses an exhibit on the biomass process and sustainable construction. The green roof is part of the curriculum. An outdoor pathway lets students observe how rain water not absorbed by the roof is filtered, then channeled through newly created rain gardens and bio-swales to replenish nearby wetlands.