Ultra-efficient. Comfortable. Affordable. Now. Phius (Passive House Institute US) provides training that enables building professionals to apply passive building principles to design and build ultra-efficient residential and commercial structures that meet the Phius Standard. Phius promotes awareness through certification protocol development, training, professional and project certification, project quality assurance, conferences, workshops, appearances and educational efforts. Passive building principles include using super-insulation, super-tight building envelope design and construction, extremely efficient windows, energy recovery ventilation, and passive solar strategies. Buildings designed and constructed using these principles can consume as little as 10 to 20 percent of the energy conventional buildings use for heating and cooling. PHIUS was founded in 2007 by Mike Kernagis, a builder, and Katrin Klingenberg, an architect. Klingenberg studied passive building principles in Germany. She has built her own residence to the passive building standard, as well as several affordable housing projects in partnership with Kernagis. Since founding Phius, they have worked to advance the passive building standard across North America. Phius strives to make passive building methods and the Phius standard the mainstream building energy standard for new construction and retrofits.