Sweden’s round passive house

Developers Simone Kreutzer and Tommy Wesslund have recently completed work on an eco-home in Sweden, clad in Kebony. Villa Circuitus, meaning ‘a going around’ in Latin, is a spacious, circular 175 sq. m passive house containing four bedrooms and open plan kitchen and dining area.

The Villa Circuitus was built to meet passive house requirements, with strict environmental demands in terms of design and construction materials. Both Simone Kreutzer and Tommy Wesslund are certified passive house experts with special expertise in energy and ventilation, knowledge they brought to the design of their latest project. They were the creative minds behind this project and cooperated with Nina Sandahl from SAJT Arkitektstudio to design the bespoke home, Sweden’s first circular passive house.

The house has a 35 sq. m veranda on the second storey, from which residents can view the beautiful landscape. Surrounding this veranda is a balustrade with integrated solar panels, which make the home self-sufficient for most of the year. The round shape is carefully designed to expose the smallest surface possible to the outdoor air and thus reduces heat loss. Large windows around the perimeter of the building allow lots of natural light to illuminate the property throughout the day and also help heat the building. Every window is custom made to retain twice as much heat as normal windows and the air circulating through the house is kept at a steady temperature by a two stage heat exchanger which passes the air through a ground based water heater then a post-heater. This two stage process efficiently warms the air in winter to a temperature of 18.5°C – 20.5°C and cools it in summer so the air circulating is 16°C - 17°C.

Alongside these high-tech elements is the widespread use of natural, environmentally friendly construction materials. Recycled paper and glass are used throughout the structure and the whole house is built on a wooden frame with Kebony cladding. Kebony is a modified softwood that acts as a sustainable alternative to tropical hardwood. Developed in Norway, the Kebony technology is an environmentally friendly, patented process, which enhances the properties of fast growing sustainable softwood with a bio-based liquid. By impregnating the wood with furfuryl alcohol, the wood’s cell wall is polymerised resulting in greatly improved durability and dimensional stability.