Passive House Podcast

In this bonus episode of the Passive House Podcast, Michael Ingui is live on the expo floor of the ZEB Summit in Dublin, Michael chats with attendees about what's scaling Passive House in their world. Guests explain how Passive House reached 7% of residential output in the Republic of Ireland, what post-occupancy data shows for Scottish social housing, and why Cairn Homes uses AeroBarrier to protect its construction schedule.

Thank you to Aeroseal for sponsoring this episode and supporting the team's trip to Dublin.

https://www.zebsummit.com/

Featured in this episode:

In this episode of the Passive House Podcast, Michael Ingui talks with Tomás O'Leary of the mosart Group about scaling Passive House across massive residential developments in Ireland and the UK. Fresh off a tour of Cairn Homes' Passive House neighborhood outside Dublin, Tomás shares the approach behind delivering certified Passive House at scale — from early benchmarking and training contractors directly, to building a team of certifiers with a direct line to the Passive House Institute. The conversation also touches on post-occupancy monitoring, tenant feedback, and Tomás's upcoming visits to Massachusetts and New York this October to sh...

In this episode of the Passive House Podcast, Michael Ingui talks with Josh Dorfman, co-founder of Plantd and host of the Supercool podcast. Josh and Michael dig into some of the most exciting solutions Josh has covered on Supercool and discuss the growing recognition among lenders and insurers that high-performance buildings are simply lower-risk investments.

https://www.plantdmaterials.com/

https://getsuper.cool/podcast/

Join us on the Reimagine Buildings Collective: https://collective.reimaginebuildings.com/

Thank you for listening to the Passive House Podcast...

In this episode of the Passive House Podcast, Ilka Cassidy talks with Ace McArleton and Jacob Deva Racusin, co-founders of New Frameworks. Ace and Jacob share how their paths through natural building and site-based straw bale construction led them to develop panelized straw wall systems, and reflect on the industry's need to break down silos between design, fabrication, and construction.  Ace and Jacob also preview the Reimagine Buildings Collective's month-long bio-based panelization lab, featuring manufacturers from across North America.

Podcast with Jay and Ace: https://passivehouseaccelerator.com/podcast/247-natural-materials-and-collective-power

Join us on the R...

In this bonus episode of the Passive House Podcast, Zack Semke talks with Katrin Klingenberg, co-founder and co-executive director of Phius, about the origins of the organization to today's growing national movement. The conversation  looks ahead to PhiusCon 2026 in Phoenix, October 8-10.

Attend PhiusCon: https://phius1.zohobackstage.com/PhiusCon2026

Join us on the Reimagine Buildings Collective: https://collective.reimaginebuildings.com/

Thank you for listening to the Passive House Podcast! To learn more about Passive House and to stay abreast of our latest programming, visit passivehouseaccelerator.com. And please join us at one of o...

In this episode of the Passive House Podcast, Ilka Cassidy talks with Michael Jemtrud, professor of architecture at McGill University and chair in Architecture, Energy, and Environment, about his interdisciplinary research lab's work bridging design education and offsite construction. Michael discusses McGill's Reconstruct program and the development of tools to close the "over the wall" gap between architects and manufacturers. The conversation explores how teaching students to think like "virtual framers" could give the next generation of architects a real advantage entering the workforce.

https://aeechair.research.mcgill.ca/en/

Join us on...

In this episode of the Passive House Podcast, Mary James and Jay Fox talk with Tom King, founder and CEO of TKF, about his all-in-one factory-built HVAC and hot water system, the Hydropod. Tom traces the company's origins, highlighting  NYSERDA-funded pilot projects at Syracuse University and a low-to-moderate income housing community in Phoenix, New York. The conversation covers the practical realities of retrofitting very different building types and how TKF has redesigned the Hydropod for its commercial launch based on lessons learned from two years of real-world installation and monitoring.

www.tkfabricate.com

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In this episode of the Passive House Podcast, Ilka Cassidy talks with Rob Leonard, a longtime builder and prefabrication specialist who helped develop the BuildSmart panel system and now leads PHIUS's Trades Training Program. Rob traces his path from decades in the field to pioneering panelized construction. Rob also shares what's next for industrialized offsite construction, from micro-factories to AI-assisted quality control, and reflects on workforce development as one of the most urgent challenges facing the building industry.

Beeson Acres Resources LLC: https://www.beesonacresresources.com/
Phius Trades Training Program to Help Shape the Future of...

In this bonus episode of the Passive House Podcast, Brent Davidson and Brynn Cooksey discuss what’s changed in the heat-pump world, what architects, engineers, and contractors need to understand, and where the industry still needs to improve. They preview the U.S. Heat Pump Summit and why bringing the right people together could be key to getting heat pumps right at scale.  

The conversation also sets the stage for Passive House Accelerator’s upcoming Heat Pump Solutions initiative, where collaborative Labs will help shape a public Heat Pump Solutions Symposium this October.  

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In this episode of the Passive House Podcast, Ilka Cassidy talks with Evan Greulich, project architect and manager at Quinn Evans, about his work bringing high-performance building strategies to affordable housing and, increasingly, to schools. Evan and Ilka chat about The Hammond at Greenmount Park, a new 109-unit affordable housing project in Baltimore and John Burroughs Elementary School in Washington, DC. The conversation covers the practical tradeoffs of building near-Passive performance without certification, the challenges of balancing historic preservation with airtightness and insulation strategies, and why Evan believes the biggest opportunity for passive building growth lies beyond housing.

In this episode of the Passive House Podcast, Ilka Cassidy talks with John Loercher, Passive House consultant, architect, and longtime Phius instructor with Northeast Projects. The conversation covers how the Phius standard has evolved since 2015 as well as growing industry attention to embodied carbon, hygrothermal modeling, and materials like straw bale construction. John also reflects on his years building the Phius Alliance New York chapter, the value of regional Passive House communities, and what excites him about expanding into new climates like Colorado's high elevation and PhiusCon's move to Phoenix.

www.ne-projects.com
https://www.linkedin...

In this episode of the Passive House Podcast, Mary James is joined by UK-based architects Dominic O'Riordan and Alan Budden, both Passive House designers who opened their homes for the UK's Passive House Open Days during a record-breaking heat wave. Dominic and Alan discuss how their buildings performed under extreme heat, the shading strategies they wish they'd fought harder for at planning stage, and why attitudes toward mechanical cooling in the UK are shifting fast after decades of treating air conditioning as unnecessary.

 EcoDesign Consultants: https://www.ecodesignconsultants.co.uk/
Article mentioned by Zack: https://www.n...

In this episode of the Passive House Podcast, Matthew Cutler Welsh talks with Johann Betz, founder of Christchurch-based Offsite Design Ltd and a board member of OffsiteNZ. Johann's work focuses on helping designers, manufacturers, and builders deliver high-performance timber buildings through design-for-manufacture-and-assembly (DfMA) and offsite construction principles.  The conversation traces the history of panelized construction in New Zealand, why past attempts at large-scale prefab factories have struggled without a pipeline of designs built for manufacture and assembly, and why a shared framework for offsite delivery could improve quality, reduce risk, and make Passive House-level performance more scalable and repeatable a...

In this episode of the Passive House Podcast, we speak with Sven Maxa, founder and co-director of Melbourne-based Maxa Design, an award-winning practice specialising in high-performance, sustainable homes and Passive House design. A Certified Passive House Designer, Sven has been at the forefront of energy-efficient residential design in Australia for more than two decades, helping demonstrate that healthy, comfortable, low-energy homes can also be beautiful and practical.

Sven shares his key takeaways from the THRIVE Passive House Conference in Melbourne, reflecting on the growing momentum behind high-performance building across Australia. We discuss the significance of major volume...

In this episode of the Passive House Podcast, Jay Fox talks with Nakita Reed, Senior Director for Preservation Operations at the African American Cultural Heritage Action Fund. Nakita discusses her new role bridging preservation, equity, and sustainability, the Action Fund's work funding projects like conserving Black modernism and stewarding sites such as Nina Simone's childhood home, and the ongoing tension between historic commissions and building owners pursuing energy retrofits. The conversation dives into practical guidance for practitioners tackling historic building and closes with a look at where the field is headed as deep energy retrofits of historic buildings become...

In this episode of the Passive House Podcast, Matthew Cutler Welsh talks with Andy Marlow, director at Envirotecture and Passive House Design and Construct, for a recap of Thrive 2026 in Melbourne. Andy shares his take on the growing presence of volume builders and even a retirement living provider at the conference, the ongoing challenge of scaling prefabrication despite its clear advantages, and how ventilation and airtightness are being marketed as premium upgrades in the broader housing market. The conversation also touches on Australia's patchy policy landscape around retrofits and property incentives, new products spotted at the conference, and what's...

In this episode of the Passive House Podcast, Ilka Cassidy talks with Michelle Apigian, Managing Principal and ESG Director at ICON Architecture, about the moment that changed how she thinks about building design, Icon's path to becoming a high-performance practice in Massachusetts, and the unique challenges of bringing Passive House principles to occupied and existing buildings. Michelle also shares her wish list for the industry and where she believes architects have the most power to make a difference.

https://www.iconarch.com/
Join us on the Reimagine Buildings Collective: https://collective.reimaginebuildings.com/

In this episode of the Passive House Podcast, Jay Fox talks with Mikhail Haramati, NRDC's state industrial decarbonization lead, about her path from California energy efficiency programs and policy work at UC Berkeley and LBNL, through the California Energy Commission and NYSERDA, to her current focus on embodied carbon in building materials.

They discuss the scale of the problem (cement and concrete alone account for about 8% of global emissions) and state-level policy momentum like Buy Clean initiatives and New York's Executive Order 22, which mandates EPDs and sets GWP limits for key materials. The conversation covers pathways to...

In this Episode of the Passive House Podcast, Ilka Cassidy shares on-the-ground interviews from Green Building United’s Sustainability Symposium in Philadelphia, highlighting regional policy, incentives, and high-performance affordable housing work. Ilka chats first with  Rich Freeh  and  Emily Pugliese  of Green Building United about Pennsylvania’s divided political landscape, lagging energy code adoption and advocacy opportunities including Philadelphia’s push to adopt 2021 IECC residential code. Ilka also chats with  Justin Lovenitti and  Norm Horn of New Ecology about  Energize Delaware programs and case studies in  Philadelphia.

https://greenbuildingunited.org/event/2026-sustainability-symposium/

https://w...

This episode of the Passive House Podcast was recorded during the Passive House Network conference in New Haven, Connecticut, hosted at the first certified Passive House hotel in the U.S. Hotel Marcel. Ilka Cassidy chatted with Ken Levenson about the theme “Profit by Experience” and Architect of Hotel Marcel Bruce Becker. Ilka also talked to other attendees like Timothy Lock, Beth Campbell, Karen Ramsey, and Cheryl Saldanha. They discuss Massachusetts code-driven Passive House growth, grid benefits, trade training access, community value, resilience, and the need to address cost, risk, and more in-person collaboration.

https://www.hotelmarcel.com...

Passive House design and construction is a team sport. It requires effective strategies and cooperation, but also precision in the field and the ability to tweak and recalibrate systems once the building is complete. A robust envelope may be the superpower of Passive House construction, allowing for downsized mechanical systems, electrification, and reduced stress on the energy grid, but these benefits are only achieved if everything works as intended.    

In this episode, host Zack Semke shares selected clips of conversations from the Reimagine Collective. Featured speakers include Carmel Pratt of ZAZNRG and Passive House New York on pos...

In this episode of the Passive House Podcast, Mary James and Ilka Cassidy speak with Joel Callow, building physicist and founding director of UK consultancy Beyond Carbon, about scaling certified Passive House delivery in London. Callow explains the firm’s focus on whole life carbon, compact building forms, overheating avoidance, and early-stage design input, and notes the team has grown to 12 people with recruitment challenges as UK training ramps up via the Passive House Trust. He describes Beyond Carbon’s role in helping major developer Barratt adopt Passive House—through lobbying, 12–18 months of R&D, and cost and constructability work—lea...

In this episode of the Passive House Accelerator Podcast, Ilka Cassidy chats with Marty Josten and Ashley Wisse of New Ecology. Marty and Ashley describe the nonprofit’s 26-year mission to preserve and improve affordable housing through sustainability, building performance, health, and resiliency, using a hybrid fee-for-service and grant-funded model. They discuss evolving embodied-carbon requirements, regional market differences, misconceptions about Passive House cost, and innovations like drain water heat recovery, as well as engaging lenders and maintaining focus amid political and funding pressures.

https://www.newecology.org/

Thank you for listening to the Pa...

In this episode of the Passive House Accelerator podcast, Ilka Cassidy interviews Nathan Kipnis, founder of Kipnis Architecture and Planning in Chicago and Boulder, about his path from early solar architecture influences during the 1973 oil embargo to today’s fact-based, certifiable Passive House practice. Kipnis explains how early rule-of-thumb passive solar design often led to overheating, and how building science and climate-specific approaches improved outcomes.  And describes his firm’s “high design and low carbon” approach, evolving client communication from quietly implementing efficiency measures to showcasing performance and resilience through smart home monitoring, batteries, and high-quality envelopes.

In this episode of the Passive House Podcast, Michael Ingui and Ilka Cassidy to share their interview with Dr. Wolfgang Feist from the 35th International Passive House Conference in Essen and discuss where Passive House is headed. Dr. Wolfgang Feist emphasizes focusing on documented, evaluated projects, the importance of integrated component systems. Looking back, he credits early collaboration with Swedish researchers and the push to build real demonstration projects, and he reiterates that the five principles remain unchanged because “physics is right.”

Thank you for listening to the Passive House Podcast! To learn more about Passive House and...

In this episode of the Passive House Podcast Ilka Cassidy and Michael Ingui, are at the International Passive House Conference in Essen and share rapid-fire interviews focused on scaling Passive House. With questions based on Michael's presentation at the conference focusing on moving Passive House from niche to necessary by reframing it as risk mitigation and engaging adjacent sectors like insurance, real estate, finance, and policy. Interviewees describe scaling through large-volume delivery, education,  supportive codes and incentives, and manufacturer-led training.

With interviews from:
Tomas O'Leary

Ann-Marie Fallon

Ken Levenson

Alexander G...

In this episode of The Passive House Podcast, Matthew Cutler - Welsh interviews Elizabeth and Everett Norris from their newly completed Christchurch home. They describe their Port Hills site on Huntsbury Hill, bought after the 2011 Canterbury earthquakes, and discuss the area’s microclimate and west–northwest-oriented design. They share challenges including long build times, working largely solo, living on site after a robbery,  and more. They detail the key lessons on early builder input, avoiding rushed window orders, daylight implications of eaves, and airtightness detailing.

https://www.designmake.co.nz/people.htmlhttps://www.everhomes.co.nz/blank-1
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In this episode of the Passive House Podcast Jay Fox interviews Vermont filmmaker Allie Rood about her documentary Prickly Mountain and My Design Build Life, which traces the design-build architecture movement that began in Warren, Vermont around 1963 and influenced design-build programs nationwide. Rood explains her personal connection through her father’s work in the community, the movement’s roots among Yale architects reacting against the designer/builder class divide, and ideas like Dave Sellers’ “Wild Beam Theory” of improvisational building. She contrasts early sculptural ski houses with a later sustainability-focused generation behind the Dimetrodon co-housing project and discusses Yestermorrow’s emergence...

In this episode of The Passive House Podcast, Mary James chats with Nidhi Shah, a certified Passive House designer and member of the Reimagine Buildings Collective. Shah traces her path from early sustainability interests in India to Passive House training in the UK. They dive into her retrofit-focused work with Retrofit Action for Tomorrow (RAFT), emphasizing whole-building approaches over piecemeal measures like external wall insulation or heat pumps. Nidhi  describes how funding criteria centered on operational carbon shaped retrofit decisions for cash-strapped public-sector buildings, and why reducing demand and peak heating loads matters alongside electrification and comfort.

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In this episode of The Passive House Podcast, Matthew Cutler-Welsh speaks with Andreas Goetz about building the Wunderbar Passive House in Orewa, about 40 minutes north of Auckland. Originally from Germany and motivated by comfort and health, Goetz pursued Passive House despite local challenges, choosing a simple rectangular ICF design with imported European triple-glazed windows and integrated exterior shutters to manage overheating without mechanical cooling. The home uses whole-house ventilation, achieved near 0.6 ACH50 airtightness, has low power bills, and added solar projected to pay back in four years, while also earning Homestar V5.

https://wunderbar-passive-house.org/

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In this episode of The Passive House Podcast, Ilka Cassidy and Jacob Racusin are at the BuildingEnergy Boston 2026 Conference (Sponsored by New Energy Works).

Ilka and Jacob recap day 2 of the conference including a keynote by Melissa O’Mara and Kevin Stack, “Unstoppable Inner Resilience and Generational Leadership,” which guided attendees through a meditation connecting to ancestors and future generations, highlighting accountability, leadership, and the “knowing-doing gap” via the Inner Development Goals. Ilka then interviews architect Phil Kaplan about a deep energy retrofit of a mid-century Acorn Deck House involving unexpected conditions, major structural changes, and questions about cost...

In this episode of The Passive House Podcast, Ilka Cassidy and Jacob Racusin are at the BuildingEnergy Boston 2026 Conference (Sponsored by New Energy Works).

Ilka and Jacob speak with:

They discuss...

Building science is at the core of high-performance construction, but it takes more than an understanding of psi-values and hygrothermal dynamics to actually get these buildings built. As we see in this episode, having a real-world understanding of materials science, finance, and how people actually work together is yet another component to this line of work. Granted, there’s still a lot of building science involved, as emphasized by the clips featuring Ed May and Ben Bogie, but this episode of The Reimagine Edit series of the Passive House Podcast should be a reminder that construction touches loads of ac...

In this episode of The Passive House Podcast, Zack Semke chats with Nick Nigro of Leggat McCall about the Bunker Hill Housing Redevelopment in Charlestown, Boston, a phased replacement of 42 aging WWII-era public housing buildings into 2,699 mixed-income units. Nick explains how the team committed to Passive House from day one and is using a repeatable “kit of parts”—precast lateral-load-bearing cores, prefabricated load-bearing exterior panels, and CLT floor systems—to improve speed, reduce temporary work, and lower both carbon and cost through iteration across 15 buildings. He describes early modeling, enclosure mockup testing, and construction-sequencing innovations like using the permanent elevator...

In this episode of The Passive House Podcast, Mary James chats with Kia Weatherspoon, founder of Determined by Design. Weatherspoon describes how experiences visiting her brother in prison and creating privacy during Air Force deployments shaped her belief that spaces must be felt, not just seen. She explains her mission-driven focus on affordable housing and a design process rooted in ancestry, legacy, and identity, translating community narratives into specific material and layout decisions. The discussion emphasizes bringing interiors into the integrated design team early, pushing for healthier materials amid cost and pricing-transparency challenges, and streamlining specifications to maintain budgets...

In this episode of The Passive House Podcast, host Matthew Cutler interviews New Zealand building scientist and sustainability specialist Tavis Creswell-Wells of Ecolution about overheating risk, building performance, and lessons from working in the UK. Tavis describes his path from architecture to building science, early research with BRANZ on the Building Energy End Use Study, and later experience in London with large energy modeling and rating systems including BREEAM, WELL, and Part L. He argues New Zealand’s H1 code overemphasizes insulation and lacks requirements to address overheating, while Part L includes lighting, hot water, mechanical systems, and checks at...

In this episode of The Passive House Podcast, Jay Fox speaks with Tony Daniels and Caitlin Matusewicz of Cycle Architecture + Planning about their backgrounds in high-performance design and the firm’s focus on scalable multifamily deep energy retrofits, resilience, and Passive House. The conversation covers why retrofits are harder than new construction and how Cycle aims to scale by starting with repeatable retrofit solutions. They discuss panelized overcladding and modular mechanical strategies, NYSERDA’s role via incentives and innovation programs, and broader barriers such as contracting and insurance models that enforce siloing.

https://www.c-ap.net/

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In this episode of The Passive House Podcast Jay Fox interviews Edie Dillman (co-founder and CEO of B.Public Prefab) and Karen Ramsey (founder and sustainability strategist at Building Wellness) about Fort Collins, Colorado’s Design to 2030 pilot program. They describe B.Public’s panelized, Passive House–standard prefab shell system launched in 2019 and Ramsey’s consulting work supporting Passive House projects, including rebuild efforts after the Marshall Fire and work tied to the Los Angeles fire rebuild. The conversation centers on Fort Collins’ plan to provide affordable, permit-ready, high-performance home plan sets tailored to local climate and code, with commu...

In this episode of The Passive House Podcast, co-host Jay Fox interviews Heather McKinstry and Shefali Sanghvi of Dattner Architects about their work focusing on Passive House projects, primarily affordable housing in New York City. The discussion delves into Dattner Architects' commitment to civic work, including multifamily housing, transportation, and healthcare projects. They emphasize the benefits of Passive House standards in dense urban environments, particularly in improving indoor air quality and reducing energy consumption. The conversation also touches on overcoming misconceptions about costs, the importance of third-party certification, and the educational needs of both clients and residents. The episode...

In this episode of The Passive House Podcast, host Zack Semke discusses bio-based materials and high-performance buildings with Lindsey Love from Regenerative Building Solutions. They highlight the importance of early phase energy and embodied carbon modeling, integrating natural materials in construction, and the benefits of such materials for building resilience and occupant health. They also discuss the AIA 2030 Commitment and the Materials Pledge, emphasizing strategies for small firms to implement high-impact, sustainable building practices. 

Regenerative Building Solutions: https://www.regenbuilding.com/

Link to the AIA 2030 Commitment: https://www.aia.org/design-excellence/climate-action/zero-carbon/2030-commitment