WAN AWARDS 15 Sustainable Buildings

Karuna House is an ambitious sustainable design project that was designed to meet a combination of the world’s most demanding green building certifications. The project is the first MINERGIE-certified home in North America, earning the top rating of MINERGIE-P-ECO. Additionally, it has achieved Passive House PHIUS+, LEED for Homes Platinum, and has reached Net Zero energy use by incorporating onsite solar panels. It is expected to be one of the few homes in the world certified by both MINERGIE and Passive House Institute US.

While achieving the environmental sustainability requirements of the project, the home successfully maintains a rigorous form that responds to the client’s programmatic needs. Located on the southern slope of a mountain overlooking the Willamette Valley’s rich wine region, Karuna House provides spectacular views of the hills and the town below. The building’s components are rooted to the hillside and step down in accordance with the sloping site, and the home is oriented to maximize the effect of the passive solar strategy.

Two towers mark the location of double-height spaces and vertical circulation. Wood and glass volumes contain the living spaces, and are arranged to optimise views to the south and east while graciously separating social spaces from the private and guest spaces. Sited in an area famous for its rust-coloured soil, the home’s exterior palette is composed of materials and colours that reflect the tones of its surroundings.

The super-insulated envelope is designed to be airtight. Solar heat gain is controlled through the use of exterior operable blinds that shade triple-glazed wood windows. Heating, cooling, and hot water are supplied by an efficient heat pump system, and a heat recovery ventilator provides the spaces with a continuous supply of fresh, preheated air. The home’s tight building enclosure is expected to result in the usage of 90% less heating and cooling energy than a typical home.

In addition to its rigorous sustainable goals, the project set a high standard for fine craftsmanship. The design team worked closely with a local building firm, Hammer & Hand, that specializes in high-end passive house construction. The confluence of the high design and extreme energy efficiency required extraordinary performance from the builder.