Darmstadt/Wiesbaden, Germany. Highly energy-efficient buildings are indispensable for climate protection. The 26th International Passive House Conference demonstrated that a high energy efficiency is also necessary for other reasons: social justice, good air quality for example in schools and health care buildings, and protecting the power grid against overloading are other good reasons to build and retrofit buildings in a better way. "So much of the Passive House is about health…