Mark is a founding principal and formed McGuire Igleski & Associates with Anne McGuire in 2001. He applies his comprehensive understanding of historic and contemporary construction methods to develop innovative architectural solutions that preserve the integrity of existing buildings.

Mark approaches each project with careful consideration of its cultural significance, ensuring modern solutions remain sympathetic to the original designs. Bringing extensive experience in facade evaluations, conditions analysis, and building rehabilitation, he views preservation architecture as an opportunity to enhance the cultural fabric of the built environment.

Outside the office, Mark was an instructor at the Art Institute of Chicago in their Historic Preservation program and has volunteered his expertise with various planning and development commissions in Glenview. Mark also served on the board of the Rebuilding Exchange, a non-profit that focuses on the sustainable reuse of building materials. He enjoys spending time in Arizona with his family, playing music, and riding motorcycles.