House III is a private residence constructed on an easterly sloping site in a mountain resort town in Idaho. This 4,000 ± square foot residence accommodates a family of four with guest areas and in-home office space. The clients were raised in ski resorts so they have an intimate knowledge of snow behavior including avalanche conditions. They therefore requested a flat roof because it eliminates snow drop and ice cycles. Large accumulations of snow are swept away by the wind rather than dropping on the leeward side of a pitched roof. Although the site is in a “blue” avalanche zone the avalanche potential is minimal. An integral part of the design, however, was to include avalanche barrier walls and shutters. Corten steel trellises act as both guard railings and trellises for vines which are intended to visually ground the house in the landscape and provide shading in summer. The clients requested large areas of glass to capture the majestic mountain views, especially to the south, east and north. Many casement windows were integrated in the design to catch summer breezes and provide cross ventilation. Formal tree bosques were planted to provide privacy and additional shading in summer. Since the house was just completed in June, the landscape has not yet matured. The intent is that natural grasses, wild flowers, and native brush will invade the formal planting and further ground the house in its natural mountain setting.
The structural system of this residence is one of the principal form givers of the architecture. It is a wood post and beam frame made up from three layers of glue- laminated wood beams. These beams form a modified Vierendeel truss by virtue of universal rods bolted through to form moment connections. This method allows for greater spans with less material. The majority of wood products in this residence are Idaho wood species, FSC (Forest Stewardship Council) certified, and were processed and manufactured within a 150 mile radius of the site.
The material pallet is Douglas fir glue-laminated wood posts and beams, natural concrete, cedar siding, vertical grain fir, stucco, corten steel and glass. Interior finishes are polished concrete, black granite, white marble, natural maple floors, and cabinets.
Due to the natural cross ventilation, no chillers were required for cooling, reducing the carbon foot print. An in-floor radiant heating system was utilized with 97% efficient gas fired boilers. Exposed natural concrete walls and floors in the lower level, and portions of the upper level, provide thermal mass to enhance the solar gain and radiant heating system. Only minimal forced air was required. The residence achieved a home energy rating score of 57 – well below the local requirement. This was achieved by utilizing several best practices including whole-envelope insulation, heat-recovery ventilation, radiant heat, and optimized solar gain. The home was impressively air-sealed and tested at 1.26 ARH50°. Maximizing the thermal envelope allowed for minimal mechanical equipment resulting in a quiet, efficient, healthy and comfortable home.