• With ultra-tight building envelopes and passive solar design, Passive House dwellings use only about 20% of the energy that similar, conventionally built structures do. 

    Credit: Courtesy Gregory Duncan Architect

    With ultra-tight building envelopes and passive solar design, Passive House dwellings use only about 20% of the energy that similar, conventionally built structures do. 

The Germany-based Passivhaus Institute (PHI) has severed ties with the Passive House Institute US (PHIUS), the only Passive House certifier in the United States. In an Aug. 17 e-mail letter to PHIUS consitutents, Wolfgang Feist, founder of the Passivhaus movement and director of the PHI, suspended all standing contracts—including certifier status—with the four-year-old U.S. organization due to allegations of breaches of contract and good faith.

“Evidence of PHIUS’ certification of Passive House buildings without the requisite documentation has threatened the integrity of the standard and forced PHI to terminate PHIUS’ status as an accredited Passive House Building Certifier,” he wrote.

PHIUS executive director Katrin Klingenberg denied the allegations in an 11-page letter a few days later and sought to assure stakeholders that the organization would continue with its mission. “PHIUS will continue to rigorously certifiy projects and engage knowledgeable and experienced Norther American certifiers,” she wrote.

What does the rift mean for North American builders and architects who build to the rigorous standard? PHIUS will continue to certify projects to the Passive House Building Energy Standard, but because PHIUS is no longer a licensed PHI certifier, North American designers and builders who want PHI’s blessing must submit their project directly to PHI, Klingenberg said. In addition, the Passivhaus Planning Package energy modeling software formerly distributed by PHIUS will continue to be available in the United States through independent resellers or via PHI, according to Feist.

The PHIUS will continue to issue its North American Passive House Consultant certification; PHIUS-certified consultants who wish to attain the European certification now must do so separately, by taking the Passivhaus Institute’s CEPH exam. (PHIUS will no longer administer that exam, but other U.S. organizations, such as the Passive House Academy in New York, will continue to offer it.) PHIUS will offer a shortened version of its North American exam to practitioners who already have the CEPH certification and would like the PHIUS designation.

Gregory Duncan, a New York City architect with credentials from both institutions, says despite the organizations’ difference of opinions the benefits of building to the Passive House standard remain unchanged: “Lower utility bills, reduced noise, and better indoor air quality are just a few,” he points out.

Jennifer Goodman is Senior Editor of EcoHome.