Passive House Podcast
Passive House Podcast
Matthew Cutler-Welsh, Zack Semke, Mary James, and Ilka Cassidy
Interviews with the leaders, practitioners, and change-makers in the global Passive House movement. A production of Passive House Accelerator.
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-haramatihttps://collective.reimaginebuildings.comhttps://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.
Jul 1
1 hr 4 min
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.
Jun 23
1 hr 11 min
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.
Jun 16
58 min
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.
Jun 12
43 min
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.
Jun 9
55 min
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.
Jun 2
55 min
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 websiteNHA websiteProject profile for Evanston’s first Passive House in PHIUS’ databaseCrain’s Chicago Business Notable Leader in Sustainability 2025 recognitionThank 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.
May 27
49 min
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.
May 19
30 min
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'LearyAnn-Marie FallonKen LevensonAlexander Gard-MurrayIn ChoFrancesco NesiGünther JedliczkeEsra AydinogluThank 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
May 12
1 hr
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-1About their amazing straw bale Passive House in Christchurch: https://sustainableengineering.co.nz/casestudy/norris-strawbale-passive-house/
May 5
59 min
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