Kroon hall's tall, narrow shape and east-west orientation reinforce the active and passive strategies used to heat and cool it. The lowest floor is set into a hillside, with only its south side exposed, providing thermal insulation and increasing the amount of natural light that enters the building. A south-facing colonnade encourages activity to spill outside. Thick walls of Briar Hill sandstone on the north and south façades have operable, high-performance windows set deep within precast concrete surrounds to shade from summer sun. Raised above the walls is a barnlike roof supported by arched frames of laminated Douglas fir. The roofline, lined in red oak (half of which comes from Yale’s own forests), creates a third-floor loft that houses an auditorium, two classrooms, a café, and a large common room. A 100-kilowatt photovoltaic array on the rooftop supplies 25 percent of the building’s electrical need.
Low-velocity fans in the basement keep the air circulating almost imperceptibly. Fresh air is fed into the building through this system in summer and winter. But in spring and fall the mechanical systems are shut down, and occupants (prompted by color-coded lights) open the windows for ventilation. A rainwater harvesting system channels water from the roof and grounds to a garden in the south courtyard, where aquatic plants filter out sediment and contaminants.
Read the full article: http://www.architectmagazine.com/sustainability/kroon-hall.aspx