About C2
C2 Architecture provides full-service architecture, interior design, and planning for residential and light commercial clients. We specialize in high-performance, custom projects with modest budgets. Founded in 2005 by Ilka and Jim Cassidy, C2 makes its home in Germantown; 85 percent of our work sits within a 10-mile radius of our studio and comes from repeat clients and positive referrals.
We aspire to create spaces that are beautiful, comfortable, well-organized, and sustainable. We approach each project with respect, an open mind, and optimism, helping us identify the inherent potential, regardless of size or budget. Our deep sustainable design and Passive House experience enables us to incorporate thoughtful approaches to energy efficiency, materiality, and embodied carbon – regardless of whether a project pursues certification. From design through construction, we see the process as a dialogue between the client, architect, consulting partners, builders, and tradespeople, where all ideas are valid and encouraged.
Approach
Architecture is about solving complex problems within the allocated budget. We design appropriate solutions that aren’t hindered by preconceived notions or what’s been done before – we create the best design for each individual client, typology, and site. Our clients come to us with problems to solve: How can we make our house function better? How can we envision a new home for retirement? How can we transform a commercial property? We respond with ideas that emphasize environmental responsibility, maximize space, and consider history, materials, and neighborhood context.
We push clients outside their comfort zones – to discover new possibilities.
We engage with builders early – to find opportunities to add value.
We treat everyone like family – to encourage positive outcomes.
Services
Architectural and interior design and documentation
Planning and programming
Construction administration
Consulting on zoning, historic, and land development issues
Sustainable design consulting and energy modeling
Certified Passive House consulting
Land and project development
Our Team
Ilka Gronert Cassidy, CPHC
Founder/Partner
A Certified Passive House Consultant (CPHC), Ilka infuses her deep knowledge of Passive House construction, natural materials, and prefabrication to support low-carbon buildings. She connects the dots – seeing projects as a whole and delving into the smallest technical details through energy modeling and analysis. Her insights make C2 architecture perform better.
Ilka grew up in Germany, received her Diploma of Engineering/Architecture from RWTH Aachen University, and won a scholarship to study with the University of Seattle graduate program. In addition to her role at C2, Ilka co-founded and consults for Holzraum System, a company that provides prefabricated and high-performance construction consulting and education. She is a member of Green Building United and a founding member of its Passive House predecessor group, and a participant in the Northeast Sustainable Energy Association (NCSEA) and member of its Building Energy Boston 2025 content committee. Ilka also cohosts regular podcasts and weekly Live! construction tech events for Passive House Accelerator, an organization that serves as a catalyst for zero carbon building.
Ilka maintains a strong connection to the outdoors and nature in her work and life. Traveling and camping with her family offer new opportunities to see the plant and animal world holistically.
Jim Cassidy, AIA
Founder/Partner
A creative designer who can quickly see opportunity in unexpected places, Jim puts clients at ease while pushing them out of their comfort zones. Jim’s strength lies in translating vision to architectural vocabulary, helping shift from words to forms. A collaborative leader, he brings out the best in his team and their work.
Jim earned a Master of Architecture from the University of Washington and dual B.A. in Architecture and B.S. in Civil Engineering degrees from Lehigh University. He received a scholarship for graduate study at RWTH Aachen University in Germany and worked in Cologne. He is a registered architect in Pennsylvania and New Jersey and accredited through the National Council of Architectural Registration Boards (NCARB).
Jim serves on the boards of the Waldorf School and Historic Germantown. Since 2006, he has taught professional management and design studio courses as an adjunct professor at Jefferson University. In his free time, you might find Jim enjoying a beer with friends, camping or traveling with his wife and three daughters, or attending a concert. A Germantown resident, Jim is proud that much of the firm’s work falls within a few-mile radius of his home and office.
Joe DiCicco, RA
Project Architect
After beginning his career as an accountant, Joe pivoted to architecture where his balance of creativity and coordination come together. Joe’s especially good at client relations, able to align expectations with reality, help visualize concepts, and coordinate engagement with consultants and construction partners. His organization and follow-through help C2 realize projects successfully.
Joe received his Bachelor of Architecture degree from Philadelphia University (now Jefferson University) where he is an adjunct professor of design foundation studios. He is a registered architect in New Jersey and accredited through the National Council of Architectural Registration Boards (NCARB). Part of the C2 team since 2008, Joe appreciates the opportunity to wear many hats, from designer in the office to overseeing construction in the field.
He and his partner live in an 1870s farmhouse that Joe has been renovating. When he’s not working on the house, Joe enjoys gardening and traveling the world for inspiration.
Robert Whalley
Project Architect
After a career in the art world, Rob went to architecture school in his late 30s. Switching gears later in life keeps him focused and continuously learning. Whether through art or architecture, Rob has always been interested in how people move through and use space, and his thoughtfulness comes through in every project.
Rob holds a Master of Architecture from the University of California at Los Angeles (UCLA) and a B.A. in Fine Art from Sheffield Hallam University in the U.K. His art career included roles as a designer and project manager for large-scale public artwork installations, and as a supervisor for installation and management of corporate collections across the U.S. and Europe. He also completed a major design project for Galveston Artist Residency, transforming existing buildings into an artist collective with studios, galleries, and offices. Rob’s involvement in every aspect of design – from building renovations to logo to furniture – demonstrate his attention to every detail. He joined C2 in 2016.
Rob lives in West Philadelphia with his wife and daughter. He enjoys visiting museums and galleries. A longtime fan of jazz, he recently took up the saxophone.
Certified Passive House Consulting
C2 Architecture maintains a deep commitment to sustainable design. Perspectives have shifted in terms of what makes a home or building sustainable. We take a broader view beyond energy efficiency to also look at material choices, embodied carbon, operational efficiency, and occupant comfort and health. Our goal remains to design the very best buildings for our clients, and we take these factors into consideration regardless of whether or not a client will pursue a certification program. For those who desire a more sophisticated approach to resilience, we offer certified Passive House consulting.
Passive House is one of the world’s leading standards for safe, resilient, comfortable, and energy efficient design based on building science. The term Passive House can apply to all types of buildings, from houses to skyscrapers. Certified by the Passive House Institute US (PHIUS), Certified Passive House Consultants (CPHC) understand the core principles used to design and build to this higher standard. Passive buildings generally achieve energy savings of 40-60 percent over traditional construction, through the use of super insulation, airtight building envelopes, efficient HVAC systems, energy recovery ventilation, moisture control, high-performance windows, and solar shading. Put simply, the approach strives for a mindful and responsible balance between building fabric, building systems, site, and human activity.
C2 Partner Ilka Cassidy is a CPHC with deep experience in building science, energy modeling, energy performance systems and products, and additional certification programs such as LEED.
For more information about Passive House design, visit PHIUS: https://www.phius.org.
