Ilka Cassidy

Ilka Cassidy, Dipl.-Ing. Architecture, CPHC, is the co-founder of C2 Architecture and Holzraum System, with a deep passion for Passive House envelope design and building science. She focuses on the benefits of using natural building materials and specializes in offsite construction.
With extensive experience in Passive House consulting and energy modeling, Ilka has a strong understanding of energy efficiency strategies. As a co-founder of C2 Architecture, she brought a sustainable design perspective to the firm from its inception. Through Holzraum System, she has worked to merge the precision and scalability of prefabrication with the use of healthy, low-carbon materials, all while optimizing energy efficiency with Passive House principles.
Ilka is also committed to expanding knowledge in the industry, serving as co-host of the Passive House Accelerator Podcast and Live events. She is a frequent conference speaker and an active member of Green Building United in Philadelphia as well as a visiting educator at McGill University.