Set in the landscape, Terrain House 800 fits snugly in the sloping terrain of many developed Cape Cod sites – an accessory dwelling with minimal presence and intrinsic sustainability characteristics. Situated below grade, its 800sf of living area barely obstruct the view from a site’s primary residence, nor impacts the local building density. Sustainable design strategies include thermal mass, green roof, natural ventilation and passive solar principles.

Utilizing the earth’s thermal mass as well as a green roof, the design mediates temperature swing providing a massive heat sink. It also shields against solar heat and chilled winter air. The earth bounded concrete walls and floors afford a stable cool mass against the summer heat. In winter, the below ground design restrains outdoor cold air from most of the building envelope, utilizing the earth's higher temperature compared to the air. In summer, the below grade envelope is shielded from the sun’s radiant heat. Earth surrounds the house on three sides of the lower level and two of the upper level.

Eastern fenestration supplies morning light to the bedroom. Southern and eastern fenestration and walls provide exposure to the low winter sun, creating opportunities for passive heating strategies that employ insulation and thermal mass. Natural air intakes access cool air pockets below grade, while hot air ventilates through operable skylights.

The Terrrain House proposal was developed for Add-On '13 in Wellfleet, MA.