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Green Building News

Rival Passive House Groups Fail in Trademark Attempts

Two groups promoting Passivhaus construction, one in Germany and one in the U.S., have failed to be issued trademarks

The U.S. Trademark Office has dismissed an attempt by the founder of Germany’s Passivhaus Institut to trademark the term “Certified Passive House.”

The decision settles a legal dispute between Passive House Institute U.S. (PHIUS), an Illinois-based organization, and Dr. Wolfgang Feist, founder of the Passivhaus Institut in Darmstadt, Germany.

The two organizations were once closely aligned, but ties were severed in what became a messy public falling out in 2011.

The following year, Feist filed an application with the U.S. Patent and Trademark Office for exclusive rights to “Certified Passive House.” (In 2011, GBA senior editor Martin Holladay wrote an article on this issue called Can ‘Passive House’ Be Trademarked?) Feist’s application was apparently filed in response to an earlier attempt by PHIUS to trademark the letters “CPHC,” which stand for “certified passive house consultant.” For more information on the filing by PHIUS, see PHIUS Tries to Trademark ‘Certified Passive House Consultant,’ as well as a report on the history of passive house trademark filings posted on the New York Passive House website. (PHIUS was apparently unsuccessful in its attempt to trademark “CPHC.”)

PHIUS objected to Feist’s attempt to trademark “certified passive house.” When Feist failed to respond — a failure which is formally called a default — the Trademark Office in April ruled in favor of PHIUS.

Term now in the pubic domain

PHIUS founder Katrin Klingenberg announced the Patent Office decision in a blog posted on July 23.

She was apparently responding to questions as to whether PHIUS and the Passivhaus Institut were involved in some type of legal proceeding and said, “It’s worth setting the record straight.”

“PHIUS has trained nearly 2,000 professionals and, since the start of 2012, has certified 120 projects with that many more projects in the pipeline,” she wrote. “That’s a sizable constituency that would not be well-served by an entity owning the term ‘Certified Passive House’ or ‘Passive House.'”

Klingenberg wrote in an earlier blog about the origins of the term and said the phrase was first used in 1980 by William Shurcliff, a physicist and early advocate of superinsulation and other energy-efficient building techniques. The basics of what became Passivhaus construction were worked out in the U.S. and Canada in the 1970s and ’80s, she said.

PHIUS laid out its argument in a filing with the Trademark Office. “Dr. Feist didn’t dispute our claims,” Klingenberg wrote, “and the Trademark Office entered judgment for PHIUS and denied the application.”

The two organizations are still far apart, chiefly over whether there should be a single performance standard, as the Passivhaus Institut argues, or a number of climate-specific standards, as PHIUS would like to see.

“The bottom line is that we’re happy to report that while philosophical and scientific differences remain, PHI and PHIUS are not in any legal proceedings,” Klingenberg’s blog says.


  1. jackofalltrades777 | | #1

    Does this mean one can say
    Does this mean one can say that their home is a "passive house" design even though it is not certified as such?

  2. GBA Editor
    Martin Holladay | | #2

    Response to Peter L
    There is no principle in American law preventing anyone from bragging that they live in a passive house, or that the food they eat is all-natural.

    However, there is a legal definition for the term "organic." If you have a roadside vegetable stand, remember that.

  3. Ken Levenson | | #3

    a fuller review of trademark issues
    may be found on the NY Passive House website:

  4. GBA Editor
    Martin Holladay | | #4

    Response to Ken Levenson
    Thanks for your comment. I have added a link to your roundup in the story.

  5. knez | | #5

    Trademark history
    Thanks Scott for following this.

    We think some additional information and clarification are warranted.

    PHIUS did establish the CPHC credential and successfully registered its CPHC mark. PHIUS developed its certification program for consultants who successfully complete its training program and pass its exams, and the “CPHC” designation by those consultants serves the purpose of distinguishing PHIUS training and certification from other programs available in the market.

    With regard to term “Certified Passive House": In 2009, when PHIUS and PHI were working in concert, Dr. Feist told PHIUS that it needed to protect the passive house terms in the United States. This led to our filing to register “Certified Passive House.” When the U.S. Patent and Trademark Office issued a response that the terminology was descriptive and appeared to be generic and not subject to registration, the effort was dropped. As you correctly report, Dr. Feist’s own subsequent application to register the term (which also claimed that Dr. Feist had exclusive rights in the terminology “passive house”) was denied when he did not contest that the terms were not subject to exclusive use of one party, but were generic terminology that all are free to use.

    Mike Knezovich, PHIUS

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