A Co-op of Certifiers dedicated to assisting you. 

We formed CertiPHIers Cooperative to support each other so we could better provide building certification to you, the growing North American Passive House Industry.  Together, pooling our talent and resources, we can accomplish large tasks. It's the same with Passive House development. It’s a team sport. We Certifiers have teamed up to assist you.  

Our motto: "Better Together." 

How we help you.

Need help modeling thermal bridges? Or completing your PHPP? Or running WUFI moisture analysis? We can help.

Want assurance you’ve created a Passive House? Or that you own a Passive House? We provide efficient, affordable Passive House building certification.

Why partner with the Passive House Institute?

CertiPHIers recognizes Dr. Wolfgang Feist's 30 years of pioneering building science and creation of the Passive House Standard, the EnerPHit Standard, and the Passive House Planning Package (PHPP) energy balance design tool. For 23 years, the Passive House Institute (PHI) has continued Dr. Feist’s scientific research and development of a global Passive House building certification program. And also an education and certification program for professionals and a certification program for high-performance building products.  

PHI is the first and oldest Passive House Institute in the world.  And the internationally-acknowledged leader. That's why we included the PHI in our name!   

Our association with PHI expands North America's access to the PHI's expertise.


Tools for Everyone (TFE)

CertiPHIers Cooperative's TFE initiative supports you by making tools and education available at the lowest possible cost. CertiPHIers developed and in 2015 started selling PHPP version 8 in American Inch/Pound units (PHPP v8.5). And again in 2018, we started North American-based sales, support, and training in Flixo thermal bridge modeling.




Meet the CertiPHIers


Tad Everhart, PHI-accredited Certifier; Owner: Tad Everhart Energy Advisor LLC, Oregon

Tad was hooked on Passive House the moment he read about it, signed up immediately for the first North American Passive House training in May, 2008, and because a Certified Passive House Consultant in January, 2009.  Tad has donated his organizational skills to supporting Passive House organizations.  Tad organized the first meetings of local “Passivists” in Portland, Oregon in 2008, then volunteered as Secretary on the first Passive House Institute U.S. (PHIUS) board of directors in 2009.   In 2010, Tad collaborated with the founders of Passive House Northwest and served as a board member from 2012 to 2018.  Tad helped organize the North American Passive House Network in 2011 and the North American Certifiers’ Circle in 2016.  With Garth Everhart, Tad developed, designed, and built 40 homes in the Portland area including his family’s home, completed in 1998—inconveniently 10 years before learning about Passive House.  In August, 2009, Tad’s family embarked on a journey to EnerPHit their home, and today, they are almost ready for certification.  Meanwhile, they enthusiastically participate in the International Passive House Open House Days  with the International Passive House Association and have hosted hundreds of tours.  Tad has certified Passive Houses since 2015 and manages CertiPHIers' operations.


Christina Snyder, Architect, CPHC, PHI-accredited Certifier; Owner: Equilibrium Energy Spaces, Michigan

Christina Snyder attended PHIUS' inaugural class in 2008 and became a CPHC in 2009, continuing a career focused on sustainable design, both in practice and education. A residential builder, an architect and sole proprietor since 2002, she also instructed architecture students as an adjunct professor, coaching them through winning the first & second Michigan Zero Energy Home competitions, as well as competing in the 2007 Solar Decathlon in Washington DC, and has also published a paper on zero energy homes utilizing seasonal heat storage systems.  Christina has been a partner in a renewable energy system installation business, Sustainable Systems, before starting her own architectural practice. She has volunteered on natural building projects including strawbale, cob, cordwood, and thatched structures; and has lectured throughout the Midwest on energy efficiency, Zero Energy Homes. Most recently she has taught Continuing Education classes for professionals on Passive Houses.  Christina is also walking her talk; she's almost completed a new Passive House on her family's Southern Michigan farm using an innovative foundation system of glass-fiber reinforced concrete structural insulated panels.  Christina has been certifying Passive Houses since 2015 and providing assistance with PHPP.

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Chris Petit CPHD, CPHT, PHI-accredited Certifier & Trainer; Owner: Regenerative Design LLC

Chris learned about Passive House and was immediately impressed by the rigor of the systems approach to construction and its commitment to reducing energy use.  Chris' commitment to low-energy buildings stemmed from his love for the environment and his passion to protect natural ecosystems.  Through his research while earning his BA in Biology cum laude from Carleton College, he decided to go beyond reporting about the disheartening trends he was seeing.  He chose to influence the built environment and the way we live, in order to reduce the large impact we currently make on the natural world with the way we design, construct, and operate buildings. 

Chris is a Passive House consultant, trainer, and building certifier accredited by the Passive House Institute. He has provided design support and energy modeling services since 2008 with the Center for Sustainable Building Research, Clean Energy Coalition and Regenerative Design. Through CertiPHIers Cooperative, Chris has consulted and certified Passive House projects in the US and Canada. In addition to his work with CertiPHIers, Chris teaches sustainable design, renewable energy, thermal bridge modeling, designPH, PHPP, and building energy-efficiency best practices and auditing. He holds a MS in Architecture from the University of Minnesota. Chris became a CPHD through training with the Canadian Passive House Institute-West and completed Certifier training at the Passive House Institute in Darmstadt. Chris has been certifying Passive Houses since 2016; provides assistance with PHPP, designPH, and Flixo; teaches Flixo; and helps manage CertiPHIers’ operations.


Rolf Jacobson, CPHC, PHI-accredited Certifier, Center for Sustainable Building Research, University of Minnesota

Rolf became a Passive House convert in 2008 after listening to a presentation by Stephan Tanner, designer of the first certified Passive House in North America (the Waldsee Biohaus).  After attending the 3rd annual Passive House Conference in the US, held in Duluth that year, he decided to focus his academic studies on the concept.  For his Masters of Science thesis, Rolf traveled to Norway in 2010 on a Fulbright fellowship to study the building science of Passive House envelopes optimized for cold climates.  While researching there for a year, he used energy and moisture modeling tools such as PHPP, WUFI, and THERM to investigate and comprehensively evaluate a wide range of residential building assemblies and details in Performance of 8 Cold Climate Envelopes for Passive Houses.  Rolf now uses these tools on a regular basis as an energy and enclosure consultant and has worked on a large variety of projects from Passive Houses to commercial buildings.  Rolf also continues to work on exciting new research opportunities as a Research Fellow at the University of Minnesota’s Center for Sustainable Building Research (CSBR).  With project partner NorthernSTAR, the center recently received a $1 million dollar grant from the DOE to help develop and construct a series of homes using a panelized, tilt-up enclosure system (SEP-ETTMS).  This system is modeled on “perfect-wall” principles of moisture safety and routinely achieves Passive House levels of airtightness while reducing construction costs.  Rolf became a CPHC through PHIUS in 2015 and resides in Minneapolis/St. Paul. Rolf provide assistance with WUFI and Flixo and teaches both programs. 


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Steve Mann, CPHD, CPHT, PHI-accredited Certifier; Owner: Home Energy Services, California
Steve has been involved in the construction industry for more than 25 years. His focus is to assist architects, contractors, developers, real estate professionals, and homeowners with sustainable design and high-performance construction practices. His primary activities include design consulting, building and HVAC testing, and sophisticated energy modeling. Steve is the designer and builder of two LEED for Homes Platinum projects. His current project is a LEED and Passive House-certified new home. His current passion is Passive Houses. He was bitten by the bug in 2010. Steve’s certifications include:

  • PHI Certifier, Certified Passive House Designer, Builder, Tradesperson, and PHIUS+ Rater.

  • LEED AP+ Homes and LEED for Homes Green Rater.

  • California-certified HERS Rater, and residential Certified Energy Analyst (CEA).

  • CalCERTS HERS Rater instructor.

  • EPA Energy Star Rater, DOE Zero Energy Ready Homes verifier.

Steve has participated in multiple subject matter expert groups for GBCI, the LEED credentialing authority, and test question writing for the California Certified Energy Analyst examination. A long-time professional writer, he is currently Senior Editor for Passive House Buildings magazine, former Home Energy magazine Contributing Editor, and former President and Board Chair of the California Association of Building Energy Consultants. Steve has been certifying Passive Houses since 2018 and provides assistance with PHPP and Flixo.

Matthew Bowers, CPHC, CPHT, PHI-accredited Certifier; Owner: Rochester Passive House Consulting, New York


Matthew Bowers spent 6 years in the Navy as a nuclear engineer and became interested in Thermodynamics and Fluid Mechanics. Once his tour was over, he attended RIT's Mechanical Engineering Technology Program where he wanted to become a HVAC designer. While at RIT he learned of “homes so efficient they don’t need furnaces”. He then focused his career path on Passive House. He graduated with the highest honors in 2010. Since 2013 Bowers has worked as a Certified Passive House Consultant and Tradesman and HERS Rater. In 2017 Matt started his own Company - Rochester Passive House Consulting - specializing in high performance homes. He has been featured in the Journal of Light Construction’s Energy Column under multiple topics including Blower Door Testing for extremely tight homes, Infrared Scanning, Blower Door Testing and Retrofitting airtightness and trouble spots for airtightness in new homes. He was the designer of Rochester’s 1st Certified Passive House – his personal home. Matt started certifying Passive Houses in 2019 and providing assistance with PHPP and Flixo.

Friends of CertiPHIers


Albert Rooks Owner, Small Planet Supply, CertiPHIers' Past Vice President, Vancouver, British Columbia, and Olympia, Washington

Albert became a Passive House enthusiast in 2009 after a long career in building materials. "The opportunity of Passive House is to both refine and excercise my personal enterprise development skills while problem solving assemblies and material requirements that aren't found within our North American supply chains." Albert helped found Passive House Northwest and served on its first board of directors in 2010. He also helped found the North American Passive House Network. Albert is currently a board member of the Northwest Ecobuilding Guild. As President and Founder of Small Planet Supply  Albert has worked with Passivhaus Institut's Dr Wolfgang Feist and staff to import the Institut's scientific studies and create tools for the Passive House Planning Package including the IP version of PHPP v8 for the American market. In 2015 Albert and Eva completed their "Corkhaus" deep energy retrofit of their condo with exterior cork insulation and many other Passive House components. Corkhaus uses cutting edge materials and is under study by two of the Northwest region's leading researchers: RDH Building Sciences for a study of the moisture movement in Thermacork expanded cork facade  and Washington State University for a study of the effectiveness of delivering both domestic hot water and space conditioning through a Sanden Eco System CO2 heat pump hot water heater.  Albert and Eva's Corkhaus in Olympia, Washington is the second home in North America where a single CO2 refrigerant heat pump water heater provides both all domestic hot water as well as all space heating without electrical resistance backup heating.  Albert contributes his marketing, sales, accounting, and small business expertise to CertiPHIers.


Sara Gundermann Small Planet Supply, Olympia, Washington

Sara has been involved in the sustainable building industry for several years, overseeing operations at The Small Planet Supply, a leading distributor of high-performance building products. She also organizes events and workshops to expand the public's knowledge of energy-efficient building practices and products. Being a “health nut” with a background in human physiology and nutrition, Sara understands the important relationship between one’s personal health and their living environment. In her free time, she enjoys working out and competing in fitness competitions, attending concerts, reading, and hiking in the Pacific Northwest.  Sara assists CertiPHIers with financial transactions and reception.


Dylan Lamar Architect, CPHC, PHI-accredited Certifier; Owner, cultivate, Eugene, Oregon

Dylan is among the leading Passivhaus consultants in the country, having designed Passivhauses since 2004 from Illinois, to New Mexico, to Oregon. He has translated the PHPP into IP-units, in 2008 and again in 2014. He has worked on many Passivhaus first’s in the nation including office/educational buildings, affordable single-family and one of the largest multifamily Passivhaus in the US. In 2010 he published Urbanize and Insulate: The Development of a Fossil-Fuel Exit Strategy, which highlights the relationship of Passivhaus toward a larger framework of societal sustainability.

Dylan worked as an architect and energy efficiency expert with Green Hammer, a design-build firm in Portland, Oregon, before starting his own firm cultivate in Eugene, Oregon providing local architectural and development services as well as national consulting services.


André Harrmann CPHC, PHI-accredited Certifier; Owner, Harrmann Consulting

André holds graduate degrees from German and U.S. universities in engineering and architecture. He is a Certified Passive House Designer (CPHD), a PHI-accredited building Certifier, and a Passive House trainer. He served on the board and as Vice Chair of the Canadian Passive House Institute West (CanPHI-West) and as a board member of the North American Passive House Network (NAPHN).
Through his Harrmann Consulting Andre provides design support, energy modelling and certification services for Passive House projects in Canada. For several years before returning to Leipzig, Germany, Andre was Project Manager for the University of British Columbia (UBC) facilitates construction projects to achieve UBC’s energy conservation targets.

André has advised on several single family and multi-unit residential buildings to achieve the international Passive House standard. He is familiar with the latest developments of the standard and has recently compiled all formulas and information relevant for Passive House in a handy compendium available at Harrmann Consulting.