A month ago, we broke ground on a two-story dormitory and academic facility (the first of two phases) for the Sugar Bowl Academy (SBA) in Lake Tahoe. Building in an extreme environment such as the Sierras presents unusual challenges, but this project poses some additional ones as this structure is being built to a very high sustainability specification. To accomplish this, we’re incorporating the principles of PassivHaus, a European sustainable building standard that is only now beginning to be implemented in the United States. We are working with Hormoz Janssens of Interface Engineering in San Francisco to aid us in accomplishing the sustainability goals.
In a cold climate, retaining heat in the winter is the primary issue, and that’s where PassivHaus applications are most significant. Typically, and even with careful construction, heat is lost through windows, building gaps, and door jambs. At the academy, the first order of business is ensuring that the building shell is ultra-heat retaining; so using a high U-value, blown-in insulation that reaches every surface is far more effective than conventional blanket insulation. A hydronic heating system, which uses super-efficient boilers, will be installed as well as energy recovery ventilators (ERV). Through a coil, the ERV recovers heat before air is exhausted, thereby capturing 60-70% of the energy that would otherwise be lost to the outdoors. The other area of extreme heat loss is through the windows and the window frame. So we have specified a high performance, argon gas filled insulating frame and high performance window system utilizing three-celled assemblies made with Serious glass.
The building’s exterior will be clad in board and batten siding with a masonry base to complement the mountain character of surrounding structures and fit well in it’s high sierra environment. The interior features high ceilings with a central skylight and side windows, providing a visual connection to the outdoors and ample daylighting for the day to day learning environment.
All of this sounds like a more expensive building; however, over the life of the building — a minimum of 50 years — the energy savings will far outweigh increased costs. Additionally, because of the highly insulated construction which loses very little heat, there is a significantly reduced need for heating. This allows the boiler required for hydronic heating to be much smaller than a conventional mountain structure. A digital control system utilizing an extensive network of sensors monitors the building’s performance and adjusts the buildings systems to respond to it’s environment in a real time. In the summer, the building is naturally ventilated, using operable windows, so no air conditioning is needed.
The site itself is adjacent to the Sugar Bowl Ski Resort, nestled in wooded area predominated by second-growth Red Firs, Lodgepole Pines, and Western White Pines and a wetland. The new dormitory and academic building will provide housing for 32 of the school’s 75-person student body. The dormitory is configured in two, three, and four-bed arrangements with two faculty apartments and a common lounge. SBA’s directors intend to keep the school a small community and are aiming to improve the overall experience for students and staff, not necessarily expand the student population. As fund-raising permits, the other phases will be implemented in the future to include a commons building with kitchen, dining, and conference rooms, an additional dorm, and a training center. Our goal was to design a simple, highly-efficient building envelope using durable materials, and one that keeps to the vernacular of the mountain environment. I’m looking forward to seeing this project through construction towards an opening in October 2013. I’ll keep you posted.