Ryan Abendroth

Principal, Passive Energy Designs LLC

Ryan Abendroth is an experienced Certified Passive House Consultant (CPHC®) and the former Certification Manager at Passive House Institute US (PHIUS). He has worked on hundreds of passive house projects including small residential designs and student projects to mid-sized commercial and non-profit developments, and he has been at the forefront of research and design in passive houses for almost a decade. His first passive house experience was with Team Illinois in the US Department of Energy’s Solar Decathlon Competition in 2009, where the team took Second Place overall.

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Abendroth is a member of the PHIUS Technical Committee and a trainer for the PHIUS CPHC Training Program, the PHIUS+ Rater Program, and advanced tutorials on topics related to passive building construction.

Abendroth also serves as the Principal of Passive Energy Designs LLC, a St. Louis, Missouri-based consulting firm specializing in achieving built high-performance and low-energy buildings that meet the passive house standard. He holds a Master of Architecture and a Bachelor of Science in Architectural Studies from the University of Illinois at Urbana-Champaign. Currently, Ryan is a lecturer at the Sam Fox School of Design and Visual Arts at Washington University in St. Louis where he teaches both graduate and undergraduate courses focused on the impacts of climate, site, energy, detailing, and building information modeling (BIM) on the built environment. Previously he taught at the Rhode Island School of Design as both a Visiting Lecturer and Critic and has acted as a passive house consultant for Kansas University’s 5th year design-build program, Studio 804.


Nick Agopian

VP Sales/Marketing, RenewAire

With over 30 years of HVAC experience, Nick Agopian is VP at RenewAire. Agopian held high-level positions at several top HVAC corporations such as Circul-Aire, Dectron Internationale and President at SEMCO. Agopian is extremely involved in the engineering and HVAC communities. He’s an active member of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) since 1983, where he sits on numerous technical committees.

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A committed lifelong learner, Agopian’s undergrad was at Mechanical Systems Engineering from Vanier College, Canada, McGill University’s Faculty of Management and recently completed an International M.B.A. from Duke University’s Fuqua School of Business.


Allison Bailes

Founder, Energy Vanguard

Allison Bailes has a broad range of experience and education, but at heart, he is a teacher. He taught physics at the high school and college level, and, after building a high-performance home in 2001, launched himself into a new career in the world of building science. For most of this new career, Dr. Bailes has run Energy Vanguard, which he founded in 2008. Since 2010 Dr. Bailes has been writing the Energy Vanguard Blog, which averages ten thousand page views per day. He also writes regularly for Green Building Advisor and has had articles published in Fine Homebuilding, The Journal of Light Construction, Home Energy Magazine, and others.

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Dr. Bailes is also popular speaker at conferences, presenting keynote speeches, breakout sessions, and extended workshops. In addition, he is a runner, a juggler, and a skier as well as having the honor of being perhaps the only man included in Who’s Who of American Women.


Jim Baldwin

Founder/CEO, Domatic

Jim has built his career as a hands-on technology leader building products and platforms for consumers and enterprises. With a degree in Computer Engineering from the University of Illinois, Jim started his career at Apple building hardware and software for human interface devices and communications systems, notably the laptop touchpad and Firewire. Jim founded Antimatter Research in 2013 to pull together great talent in hardware, software, and AI to make intelligent products. One of Antimatter’s projects took the team deep into the space of smart buildings. The opportunity to leverage modern technology to benefit builders, operators, and occupants led the team to found Domatic in 2019.


Chris Benedict

Principal, Chris Benedict, R.A.

Chris Benedict is a registered architect with 30 years of professional experience. Her office, Chris Benedict, R.A., was founded in 1995 and specializes in the design of exceptionally energy efficient buildings. A leader of the Passive House movement in the United States, Chris has designed over 80 apartment buildings in New York City, including three recently completed apartment buildings in New York City designed to meet the Passive House Standard.

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She has another 15 Passive House buildings on the boards, all designed to cost the same as typical construction. Chris is a graduate of the Cooper Union where she was inducted into the Cooper Union Hall of Fame. Chris teaches internationally about her groundbreaking work and is a thought leader in the building industry.


Derek Cowburn

Founder, LumenCache Inc.

Derek Cowburn is a values-centered entrepreneur who is passionate about the environment and making bold leaps in energy efficiency through system integration. He is a subject matter expert in building controls and intelligent DC Nanogrids, and contributes to industry working groups to promote efficient building technologies. As founder and CEO of LumenCache, he is leading the collaborative effort to globally change the standard for power distribution and controls in all new buildings, making them smart, safe, efficient, and resilient.

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Derek resides in Shenzhen, China, the high-tech electronics manufacturing capital of the world where he’s been featured for his innovations and his work with the Ministry of Housing and Urban Development. He makes time every week to participate in Passive House events where he is known to use the phrase “Put a little Active in your Passive”.


Alex De Gagné 

VP Sales/Marketing & Co-Owner, Minotair

Trained as a Building Technologist with degrees in Building Construction and Inspection, Alex has been working in technical sales for the last 15 years for major HVAC manufacturers like at Fantech-Systemair for years, a worldwide manufacturer of HVAC products. Heavily involved in the mechanical industry (previous Director on the Board of the Canadian Institute of Plumbing and Heating for 2 years, he was also Vice-Chairman of the Board of Quebec Passive House and gave presentations on Passive House to the general public. Since spring 2016 Alex leads the sales and the marketing for Minotair.

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When not roaming the roads of North America for business, Alex likes to ride his bicycle on gravel roads, go hiking, alpine skiing and enjoying the great Latin life being at home in beautiful and vibrant, French-Charming, Montréal, QC.


Brice Delhougne 

Engineering Technologist & Co-Owner, South Mountain Company

Born and raised in Paris, France, Brice is a graduate of les Compagnons Du Devoir – a highly regarded technical education program in which students spend years traveling around Europe to apprentice with the masters. Brice’s training spanned eight years with more than a dozen companies. After graduation, he used these experiences to develop training curriculums and opportunities for young professionals and apprentices across the EU, including an international passive house training between the UK and Belgium. He then joined the COSTIC, an HVAC research institution in Paris to teach energy efficiency, airtightness, solar thermal, and solar electric. For the past decade, Brice has lived on Martha’s Vineyard and worked as South Mountain Company’s Engineering Technologist alongside Marc Rosenbaum.


Josh Edmonds

Co-Owner, Simple Integrity, LLC

Based in Cooperstown, NY, Josh Edmonds manages a high performance construction firm, Simple Integrity. Josh has been involved in construction for a decade and a half. Simple Integrity made the shift into high performance construction in 2015. Since then, they have built almost a dozen high performance homes, including two Certified Passive Houses. Josh is a CPHC® and CPHB and enjoys the time that he spends designing assemblies and mechanicals for the homes they build. Simple Integrity handles all aspects of the construction process in house, which allows for a building that is designed and constructed as one integrated system.


Lindsey Elton

President, Director of Rating Services, Eco Achievers

Lindsey Elton is certified in advanced building science and building diagnostic testing. Her company, Eco Achievers, assists project teams throughout the country in constructing high-performance single, multi-family, and mixed-use buildings that meet everything from NGBS to LEED, ENERGY STAR, and PHIUS+ standards. Lindsey has been fortunate to work on many firsts as a PHIUS+ professional – from the first certified multi-family projects in IL, MN, WI, and Chicago, to the first commercial projects in IL.

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She volunteers as the Co-Vice President of PHAUS-Chicago and frequently speaks on topics related to building science and green building certification. She is a credentialed RESNET, BPI, and ENERGY STAR Rater; LEED for Homes Green Rater; PHIUS+ Rater/Verifier, and CPHC®.


Doug Farr

FAIA, FCNU, LEED Green Assoc., Farr Associates

Deemed one of Planetizin’s 100 most influential urbanists of all time, Doug Farr is a legend in his own right. He co-chaired the development of the U.S. Green Building Council’s LEED for Neighborhood Development (LEED-ND) and has served on the boards of urban sustainability organizations including the Congress for the New Urbanism, Bioregional, EcoDistricts, and Elevate Energy. He has multiple PHIUS certified projects complete and in the pipeline.

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Doug is curating an exhibit at the Chicago Architecture Center. Based on his pioneering sustainable design practice, Doug authored the urban planning best-seller Sustainable Urbanism: Urban Design with Nature in 2008 with a new follow-up, Sustainable Nation: Urban Design Patterns for the Future.


Michael Franco

PHIUS Product Certification Program Coordinator

Michael Franco joined PHIUS in October 2020 as the Product Certification Program Coordinator. Prior to joining PHIUS, Michael worked as an account manager for an MRO distributor in the industrial sector. He holds a B.S. in Business Administration from Chapman University and an M.S. in Project Management from USC.


Katy Hollbacher, P.E. 

Principal + Founder, Beyond Efficiency

Katy is a licensed civil engineer and has over twenty years experience in the A/E/C and green building industries. She founded Beyond Efficiency in 2009 and is happiest in her work when she can help clients discover their underlying motivations and define meaningful goals. She then applies whole-systems thinking to empower them with the key insights they need to make informed decisions.


Gary Klein

President, Gary Klein & Associates

Gary Klein, President of Gary Klein & Associates, Inc. has been intimately involved in energy efficiency and renewable energy since 1974. One fifth of his career was spent in the Kingdom of Lesotho, the rest in the United States. Mr. Klein has a passion for hot water: getting into it, getting out of it, and efficiently delivering it to meet customers’ needs. After serving 19 years with the California Energy Commission, he has provided consulting on sustainability since 2008, with an emphasis on the water-energy-carbon connection.

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Mr. Klein received a BA from Cornell University in 1975 with an Independent Major in Technology and Society with an emphasis on energy conservation and renewable energy. The International Association of Plumber and Mechanical Officials (IAPMO) recognized his efforts in 2014 presenting him their Green Professional of the Year award. In 2015 the Department of Energy awarded him the Jeffrey A. Johnson Award for Excellence in in the Advancement of Building Energy Codes.


Benjamin Knopp

Think Little Home Energy

Benjamin Knopp is a building science consultant at Think Little Home Energy in Charlottesville, VA. He has a background in building construction, engineering, building science and a passion for energy efficiency. Benjamin studied engineering at Virginia Tech and the Technical University of Darmstadt in Germany. At Think Little, he consults with architects, builders, and homeowners on building durability and energy efficiency. He also designs and commissions mechanical systems for high performance, low-energy homes and apartment buildings.


Nikki Krueger


Nikki Krueger is the Building Science & Business Development Manager for Therma-Stor’s residential and commercial indoor air quality brands, including Ultra-Aire whole house ventilating dehumidifiers, Santa Fe freestanding dehumidifiers, and Quest climate control. She is a RESNET certified home energy rater, a member of the ACCA Manual Low Load Homes (LLH) Advisory Committee, and sits on the building envelope committee for the Spray Polyurethane Foam Association.

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As building science manager for Therma-Stor, she educates builders, HVAC contractors, architects, engineers, crawl space contractors, and other professionals in the industry on the building science of ventilation and moisture control in buildings.

 Kimberly Llewellyn_rd

Kimberly Llewellyn

Mitsubishi Electric

Kimberly is the technical lead of Mitsubishi Electric’s Performance Construction Team which is committed to supporting builders, architects, engineers, contractors and developers nationwide in their efforts to provide high performance buildings. She works as a mechanical system consultant and educator on the subject of variable capacity heat pumps, ventilation and healthy, efficient and integrated mechanical solutions. Informed by a perspective that the built environment impacts our global ecosystem, she specializes in the advancement of high performance building practices for low carbon impact projects including passive house, net zero energy, deep energy retrofits with a particular focus on multifamily buildings.

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Kimberly began her work in the construction industry with 6 years of field work as a HERS rater and building failure consultant which shaped her holistic, field based perspective. Motto: Balance theory and practice, keep your boots dirty, hold skilled trades in high regard and refuse to gloss over inconvenient field realities.

She holds a Master of Science degree in Environmental Engineering from Columbia University, is a voting member on ASHRAE Technical Standard Committees 62.2 (Residential Ventilation and Acceptable IAQ) and 227P (Passive Building Design) Committees and is a PHIUS certified CPHC®.


Tim McDonald

President & CEO, Onion Flats LLC

Timothy McDonald is a registered architect and Certified Passive House Consultant, Builder and founding principal of Onion Flats, an award winning development/design/build collective centered in Philadelphia. He earned his Masters of Architectural History and Theory from McGill University and his BArch from Penn State, and has been teaching, practicing and lecturing widely for over 20 years.

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The firm’s focus on community development, multidisciplinary thinking, and making high-performance building technologies and alternative construction methodologies has won them many national and international awards including the 2018 and 2016 Green Building United’s Ground Breaker Award, the 2018 ULI Willard Rouse Award for Excellence, the 2015 International Passive House Award, the 2010 ULI Global Award of Excellence, and the Emerging Voices Award by the Architectural League of New York in 2008. Through his research and practice, Tim, along with his partners at Onion Flats, has developed, designed and built some of the first LEED Gold and Platinum projects in the country and the First Certified Passive House, Net-Zero-Energy-Capable project in Pennsylvania.



Al Mitchell

PHIUS Technical Staff

Al Mitchell joined the PHIUS team in July 2020 to aid in technical capacities, ranging from research to project certification. He holds degrees in architectural engineering and architecture from Illinois Tech and Ball State University respectively.



Ty Newell

Co-Founder, Build Equinox

Ty Newell is a co-founder of Build Equinox, manufacturer of the CERV Smart Ventilation System. He retired from the University of Illinois in 2007 as an Assistant Dean in the College of Engineering. Ty’s degrees are in mechanical engineering (BS,’74, University of Michigan and MS/PhD, ’78/’80, University of Utah). He has lectured around the world on indoor air quality, comfort, solar energy, building energy efficiency, and resource conservation.

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Ty lives in a 100% solar powered home in Urbana, Illinois that features automated fresh air control (CERV), two Electric Vehicles (also 100% solar energy powered), and rainwater harvesting for indoor use.


James Ortega

PHIUS Certification Manager

James Ortega joined PHIUS in February of 2015 as a member of the Certification team, where he provides design review and energy modeling services to evaluate project qualifications for PHIUS+ Certification. Ortega works closely with the submitting CPHC to provide feedback on questions pertaining to energy modeling and building plans.

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He also provides consulting services on static and dynamic energy modeling in WUFI Passive and THERM, and spearheads energy modeling deliverables on feasibility studies for projects interested in pursuing PHIUS+ Certification. Ortega holds a Bachelor of Architecture degree from the Illinois Institute of Technology in Chicago, and is currently pursuing his architectural licensure.


JS Rancourt

Principal, DXS

JS Rancourt is a Principal at DXS (manufacturer representatives for Daikin in New England, Texas and Ontario) focused exclusively in VRV/VRF and ASHP technology. JS is a mechanical engineering graduate from the University of Waterloo in Ontario, Canada, and in 2012 co-founded DXS Ontario, based in Toronto, Canada. JS has been applying ASHPs and VRV/VRF technology in cold climates for 8 years and spearheaded the largest VRV project in North America at the time with over 1,400 VRV units.

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JS moved to New England in 2016 and founded DXS New England out of Peabody, MA. JS primarily works with consulting engineers and building owners, and prides himself on educating the industry on topics such as ASHPs, VRF, refrigerants and strategic electrification of HVAC.


Sloan Ritchie 

Founder and President, Cascade Built

Sloan Ritchie is a pioneer in the Passive House movement in Seattle. As a developer and general contractor, Sloan draws on building science principles and decades of experience to guide the design and construction of buildings that use up to 80% less energy for heating and cooling. With buildings accounting for nearly 40% of CO2 emissions in the US, Sloan sees the opportunity to address climate change through designing and delivering high-quality, comfortable and efficient buildings.

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His mission is to demonstrate the scalability and feasibility of using Passive House construction techniques to build cost-competitive high-performance projects, establishing Seattle as a leader in the nation and changing the way people think about where they live and work. Sloan is a graduate of Whitman College and an MBA graduate of the University of Washington. He speaks on the topic of residential green building and Passive House. He is a sought-after expert for interviews on his approach, drive and project experience. His team and clients appreciate his approachable, calm nature and hands-on, insightful leadership style.

Off work, Sloan enjoys windsurfing and traveling with his wife, Jennifer, and their two children.


John Rockwell

Zehnder America

While designing and building his own low-energy, high-performance home in Massachusetts, architect John Rockwell became a Technical Sales Engineer with Zehnder America, the North American division of the Swiss-based manufacturer of superior indoor climate solutions. Since 2014, he has delivered presentations at hundreds of architecture and engineering firms and trade shows, and designed almost 1,000 whole-house ventilation systems with heat recovery.

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John received his Bachelor of Architecture from Wentworth Institute of Technology in Boston and his Master of Architecture from the University of Miami. When not happily immersed in building science, he sings and plays guitar in his roots/Americana band.


Marc Rosenbaum


Marc Rosenbaum, P.E. is a long-time student of making great buildings. He uses an integrated systems design approach to help people create buildings and communities connected to the natural world, supporting both personal and planetary health. Much of his recent work has been Zero Net Energy Buildings, Deep Energy Retrofits and Passive Houses. His work has been recognized nationally by ASHRAE, AIA, EEBA, and NESEA, but they didn’t see all the mistakes along the way.


John Sarter

CEO, Off the Grid Design
John Sarter is an innovator and entrepreneur in the converging fields of real estate, renewable energy, and e-mobility. The goal of his work is carbon neutrality and GHG elimination within those 3 sectors. He has owned and operated his Design/Build and Development firms, Sarter Construction & Design, Off The Grid Design, and Sol Lux Alpha in California since 1986. With Off the Grid Design, John is leading the industry in the integration and development of Carbon Neutral Living + Transportation systems.
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John Founded the Microgrid Development Group SF Bay Area in 2014 and currently consults with industry and policy leaders in the area of Zero Carbon community development, while also continuing to design and develop cutting edge innovative projects.


Galen Staengl

Founder/Mechanical Engineer, Staengl Engineering

Galen Staengl, P.E., LEED® AP BD + C, CPHC, has 20 years of experience designing cutting-edge energy-efficient mechanical systems for green building projects and industrial facilities. Throughout his career, Galen has worked to bring energy-efficient and sustainable principles into his designs for award-winning schools, institutional buildings, multi-family residential projects, and office buildings. As President of Staengl Engineering, Galen has provided design and energy analysis for buildings certified as LEED Platinum and Gold, Passive House, Net Zero energy, Net Positive energy, and Living Building Challenge.

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As a leader in low-energy building system design, Galen regularly presents and moderates at national and regional green building conferences. He is also involved in advancing the technical and regulatory aspects of green building design in the U.S.; he is currently a member of the national Technical Committee of Passive House Institute U.S. and is working with the Green Focus Group to assist the Virginia Housing Development Agency propose sustainable design guidelines for future developments.


Lois Vitt Sale, FAIA, LEED Fellow

Senior VP, Chief Sustainability Officer, Wight & Company

Lois’ 32-year career as a practicing architect has focused on sustainability as intrinsic to design aided by the application of green technologies and sustainable planning. As Chief Sustainability Officer for Wight, recently, Lois has led the effort to design five buildings to meet the criteria for Net Zero Energy. Her work continues to raise the bar for high performance, healthy buildings for the work designed and built by her firm. She has been adjunct faculty at Northwestern University since 2005. She has educated, volunteered and lent her energies to promulgate an understanding that creating places where people thrive demands deeply sustainable solutions for the built environment.


Lisa White

PHIUS Associate Director

Lisa White serves as the Associate Director for the Passive House Institute US (PHIUS) and has been with PHIUS since 2012. Prior to this role, she led the certification review team. She is an instructor for Certified Passive House Consultant (CPHC®) and WUFI Passive software training. White holds a degree in Environmental Sustainability with a minor in Architecture from the University of Illinois at Urbana-Champaign, and a Master’s in Energy Engineering from the University of Illinois at Chicago.

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White works on certification, training, and WUFI Passive development and is a member of PHIUS’ technical committee. She also provides consulting services on static and dynamic energy modeling in WUFI Passive, THERM modeling, and project planning specific to passive building principles. White has presented at numerous conferences and events, including Greenbuild, ASHRAE, PHIUS Annual North American Passive House Conferences, the Affordable Comfort Institute national conference, and Facades+.


Dan Whitmore

RDH Building Science

Being one of the first Certified Passive House Consultants in the United States, Dan Whitmore, CPHC®, CPHB enjoys delving into the minutiae of energy conservation and then translating that information into built reality. From this focus, he has participated in the design and construction of numerous groundbreaking projects across the US. In his efforts to evolve building practices, Dan combines a passion for energy, sustainability, and the natural environment with over 30 years of construction experience. He joins knowledge of Passive House, building science, materials selection, and energy resources with his extensive background in hands-on craft, site management, and project troubleshooting.


Graham Wright, Ph. D

PHIUS Senior Scientist & Chair of the PHIUS Technical Committee

Graham S. Wright is Senior Scientist at Passive House Institute US (PHIUS) and Chair of the PHIUS Technical Committee. He leads PHIUS’ research and development efforts, and worked to develop the PHIUS+ 2015 Passive Building Standard — the only passive building standard on the market based upon climate-specific comfort and performance criteria tailored to North American climate zones. Wright helped to launch and continues to provide input for the PHIUS+ Passive Building Standard and Certification program.

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In addition to his role as PHIUS Senior Scientist, Wright also established and leads the PHIUS Verified Window Performance Data Program, which evaluates fenestration components for use in passive building applications for specific climate zones. Additionally, he also serves as the Chair of the PHIUS Technical Committee, a consensus based panel of passive building experts who review technical standards and practices and publish the findings.

Wright earned a Ph.D. in Electrical Engineering from the University of Illinois at Urbana-Champaign with thesis work related to ink-jet printing, after which he worked ten years for Eastman Kodak on the development of toner-based printing technology. In 2007 he joined AmeriCorps VISTA and relocated to Minnesota to help the Rural Renewable Energy Alliance develop a durable and efficient solar air heat panel. In 2008 he served as a permaculturalist for the Hunt Utilities Group, which is where he first discovered and became involved with the passive building movement. Wright joined PHIUS first in 2011 as an instructor, in 2012 as a pre-certification caseworker, and in 2013 as Senior Scientist.