CallisonRTKL is an approximately 2,000-person architecture, engineering, planning and interior design firm headquartered in Baltimore, Maryland, with multiple offices both nationally and worldwide. Tim has over thirty-nine years of corporate management, administrative, legal practice and risk management experience, thirty-five of which have been while in-house counsel to The Architects Collaborative, Shepley Bulfinch Richardson and Abbott, RTKL Associates Inc., and now CallisonRTKL Inc.

Tim is a registered architect in numerous jurisdictions and is a member of: the Massachusetts Bar Association; the California Bar Association; the American Bar Association and its Forum Committee on the Construction Industry; He is a Fellow of the American Institute of Architects, where he is a past member and Chair of its Documents Committee, Chair of the Task Group which produced AIA's 2004 Design/Build Documents, a member of the Task Group that produced AIA's A201-2007 General Conditions, and Chair of the Task Group that produced the AIA’s 2008 integrated project delivery documents; the Boston Society of Architects (including a former member of the Board of Directors, former Commissioner of Professional Practice, member of the BSA/AGC Design/Build Task Force, and past member and chair of the BSA’s Ethics Committee); and past member of Design Professional Insurance Companies Architects Advisory Council.