This small, shell-shaped villa — made using local wood, rammed earth and traditional techniques — is located in the forest of Nagano Prefecture in the center of Japan. Known as the Shell House, the project request came from a client who wanted a contemporary and unique home that could blend into the surrounding forest with minimal environmental impact.
To blend the Shell House into the surrounding environment as organically as possible, the designers chose a rounded, shell-inspired shape and constructed the structure using locally sourced natural materials. Local, FSC-certified wood and earth went most into most of the building, with additional sustainable elements including hand-built construction and the elimination of petrochemical materials.
The entire structure was built per passive house principles to Japanese standards. The home satisfies the environmental assessment’s primary energy consumption requirements, and then some, with 11% less energy consumption than the country’s standard. Windows and doors are made of aluminum and resin composite with double- and triple-paned glass. The outside roof is made of asphalt, and the fireplace inside is also made of rammed earth. The earthen walls are combined with 180 millimeter wool insulation to complete the energy-efficient package.
Interior rooms are finished with local earth and wood as well as the rammed earth wall that makes up the curved surface of the exterior. The southeast wooden fittings are designed to become integrated with the forest through the deck, which is also made of sustainably sourced wood. According to the architects, the seven beams connected to the rammed earth wall are inspired by the cycle of human life and the universe, with the two inscribed circles representing the correspondence of them. Ideally, once the villa has reached the end of its life, the materials can be returned back to the earth.
Images via Tono Mirai Architects