Unity College’s TerraHaus, a Passive House Residence Hall
TerraHaus is a 2,100 square foot student residence hall built on Unity College’s campus in Unity, Maine. The goal of the project was to redevelop a portion of the existing campus, replacing six small, inefficient and deteriorated student-housing structures with three new energy-efficient residence halls. The project required that a portion of the existing campus be redesigned, allowing for the phased demolition and construction of the site. The first of the three new residence halls is called TerraHaus. The design approach for TerraHaus was to create a highly-insulated building shell that makes use of passive solar gain to lower space heating demands, allowing the cost and complexity of the mechanical systems to be minimized. The metric used to determine the target level of energy performance for the building was the German Passive House Standard, which represents an 86% improvement on the home’s space heating loads from code complaint construction. TerraHaus will soon be certified as the first student residence hall Passive House in the United States in February of 2012.
A building’s size and form directly impacts its energy performance, use of materials and disruption of the site. In order to optimize TerraHaus’s energy performance and long-term sustainability, a simple, compact building form was created, reducing the exterior surface area and resulting heat loss. This form also echoes the regional vernacular of the Northeast, where spare, peaked roofed structures were built for the same reasons centuries ago, and continue to be used today.
TerraHaus comfortably accommodates 10 residents with a plan that has been optimized for flexibility in a compact volume. On the first floor, public functions are accommodated in an open plan with large windows allowing a variety of concurrent uses. There are also handicap-accessible bathrooms and bedrooms. Upstairs, the space is efficiently divided into single and double rooms.
On the site, the building’s compact footprint and location maximize solar gain while creating spaces around the structure where students can park bicycles, garden and congregate. The surrounding site has been redesigned to create a network of pedestrian paths to encourage bike and foot traffic from TerraHaus to the surrounding campus. The siting of the new residence halls also creates a needed spatial structure within the campus: the cluster of these new buildings establishes the end of an informal visual axis, connecting the new residence halls to the academic buildings at the heart of the campus.