Submitted by: TB Ritter
Implemented country: Austria
Title: Commercial building with straw insulation
A showcase example of a building meeting the German passive house standard was built in 2008 in Vorarlberg, Austria. The building was constructed with wood framing and insulated with straw balls. As an insulator, straw delivers the advantages of ease of processing, low energy requirement for production and transport, no chemical treatment, and no disposal problems. The HVAC system consists of controlled ventilation with heat recovery (saves energy and improves air quality) and solar collectors integrated in the façade to cover the basic heat requirements of the building. The foundation plate and concrete floor are used as thermal mass; the solar energy is transferred to the thermal mass via piping integrated in the concrete floors. Heat is dissipated to rooms via the radiant floor heating (delayed). A firewood heating system provides backup heat on cold days. Switchable wall outlets and optimal natural lighting at workplaces ensure additional energy savings. These measures combine to yield 5000 kWh more energy than the building needs for heat and electric power. The annual energy requirement is 15 kWh/m².