The international Passive House Institute (PHI) has severed its ties with the Passive House Institute U.S. (PHIUS), as PHI’s Wolfgang Feist accuses the U.S. body of compromising the Passive House standard. PHIUS, for its part, labels Feist’s open letter an act of sabotaging the Passive House standard, and is working to mollify certified Passive House designers and projects whose credentials may be caught up in the dispute. The Passive House standard has since been admired for its simplicity, but the relationships behind it are clearly more complex. More »