Passive House Podcast

Bonus Episode: The Heat Pump Conversation You Don’t Want to Miss

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. https://www.usheatpumpsummit.com/ https://www.airdoctorshvacservice.com/ Brent Davidson:https://www.linkedin.com/in/brentdavidson/ Brynn Cooksey: https://www.linkedin.com/in/theairdoctor/ 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

302: Bringing Passive Building Principles to Schools with Evan Greulich

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. The Hammond at Greenmount Park and The Johnston Square Branch of the Enoch Pratt Free Library The Hammond at Greenmount Park – Baltimore, Maryland – Living Design Johnston Square Branch Library – Baltimore, Maryland – Learning Design Integrating Services Within Communities: Libraries as Superconnectors John Burroughs Elementary School (Modernization) Renewing Historic Schools, Part 1: Renovation Burroughs ES | dcps Green Building Advisory Council | doee 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

301: Building the Next Generation of Passive House Professionals with John Loercher

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.com/company/northeast-projects 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

300: Rethinking Cooling in the UK, with Dominic O'Riordan and Alan Budden

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.nytimes.com/2026/07/01/opinion/heat-wave-europe-america.html?unlocked_article_code=1.xlA.5iqJ._hKPg0bjq_M_&smid=url-share 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

299: The Missing Standard for Panelized Construction with Johann Betz

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 across the industry. https://www.offsitedesign.co.nz/ https://www.osm3604.nz/ 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

298: The Potential for Passive House at Scale in Australia with Sven Maxa

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 builder Metricon’s presence at the event and what it could signal for the mainstream adoption of Passive House principles in the Australian residential sector. https://www.metricon.com.au/ 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

297: Nakita Reed on Preservation, Equity, and High-Performance Retrofits

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 more routine. https://savingplaces.org/stories/building-performance-standards https://www.builtbuildings.org/dbth 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

296: Inside Thrive 2026 with Andy Marlow

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 next for Envirotecture as they relaunch their pre-designed home offering. https://www.envirotecture.com.au/ https://passivhausdc.com.au/ 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

295: Finding Agency: Michelle Apigian on the Power of Architects

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/ 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

294: Beyond Operational Carbon: Rethinking Cement, Steel, and Embodied Carbon

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 decarbonization—reuse and deconstruction, steel's reliance on recycled scrap and hydrogen-ready direct reduced iron, lower-clinker concrete mixes and SCMs, and mass timber—along with practical first steps for designers and policymakers: better data, smarter specs, and the right incentives and financing tools. https://www.nrdc.org/bio/mikhail-haramati https://collective.reimaginebuildings.com https://www.nyserda.ny.gov/ 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

293: Innovative Solutions for Affordable, Sustainable Living

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://www.newecology.org/ https://energizedelaware.org/ 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

292: Profit by Experience: Insights from the Passive House Network Conference

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/ https://passivehousenetwork.org/the-passive-house-network-conference-2026/?utm_term=&utm_campaig... 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

TRE 17: Refining the Model

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 post-occupancy data, Ed May of bldgtyp on modeling literacy, Skyler Swinford of Energy Systems Consulting with Lloyd Alter of Toronto Metropolitan University on refrigerants and water-based distribution, James Peterson of Petersen Engineering on heat pump water heaters, and Nick Nigro of Leggett McCall on what's next at the innovative and enormous Bunker Hill housing redevelopment project. The Reimagine Edit is a special series of the Passive House Podcast that shares curated insights from our Experts-In-Residence at the Reimagine Buildings Collective, our membership community of building professionals stepping up to tackle climate change. Learn more about the Reimagine Buildings Collective at https://www.reimaginebuildings.com.

• Chapters

291: Beyond Carbon: Transforming UK Housing with Passive House

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—leading to thousands of units in the pipeline and an estimated 15–20,000 London dwellings in progress. https://www.beyondcarbon.uk/ 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

290: Decarbonization and Affordable Housing: The New Ecology Approach

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 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

289: High Design, Low Carbon: A Conversation with Nathan Kipnis

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. KAP website NHA website Project profile for Evanston’s first Passive House in PHIUS’ database Crain’s Chicago Business Notable Leader in Sustainability 2025 recognition 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

288: Insights from Wolfgang Feist at the International Passive House Conference

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 to stay abreast of our latest programming, visit passivehouseaccelerator.com. And please join us at one of our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.

287: Global Insights on Scaling Passive House

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 Gard-Murray In Cho Francesco Nesi Günther Jedliczke Esra Aydinoglu 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays

286: Elizabeth and Everett's Straw Bale Passive House Journey

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 About their amazing straw bale Passive House in Christchurch: https://sustainableengineering.co.nz/casestudy/norris-strawbale-passive-house/

285: Exploring Design and Community with Filmmaker Allie Rood

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 as a design-build school. Rud also recounts the film’s 10-year production, funding and grant challenges, finding an editor, shifting to a personal narrative, and current festival distribution and screening plans. https://allieroodfilms.com/ Trailer for the film: https://vimeo.com/1125499443?fl=pl&fe=sh Reimagine Buildings: Designing for Survivability: https://events.ringcentral.com/events/reimagine-buildings-survivability/registration 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 our Passive House Accelerator LIVE! zoom gatherings on Wednesdays.