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.

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.

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.