Patrick MacLeamy

Patrick MacLeamy, FAIA, LEED AP, (born October 2, 1942, in Alton, Illinois) is an American architect who is chairman and former CEO of HOK, a global architecture, engineering and planning firm.

He has served as an industry advocate for the need to leverage new technologies and collaboration tools to improve the practice of architecture. As a founder and chairman of buildingSMART International (formerly the International Alliance for Interoperability), MacLeamy has advanced the global implementation of building information modeling (BIM) to improve the quality and efficiency of the architectural design process. He also supports the establishment of nonproprietary and interoperable standards for the exchange of data in the design and construction industry.

MacLeamy established a concept, commonly referenced in the design and construction industry as the MacLeamy Curve, to illustrate the escalating cost of design modifications as a project team progresses in the design process. His time-effort distribution curves "are among the most oft-cited sources for researchers interested in mainstreaming building information modeling (BIM) implementation in the architecture, engineering and construction (AEC) industry."

MacLeamy has practiced at HOK since beginning his career in the firm’s St. Louis office in 1967. He relocated to San Francisco in 1970 to help establish the firm’s first regional office. He was named managing principal of that office in 1983 and became HOK's chief operating officer in 2000. In 2003, MacLeamy was appointed CEO and in 2012 he also was named chairman. In April 2016, as part of a planned succession, he stepped down as CEO but remained as HOK’s chairman.

During his career, MacLeamy has served leadership roles on several prominent architectural projects, including the Moscone Center in San Francisco and the King Khalid International Airport in Riyadh, Saudi Arabia.

He is the past chairman and a current member of the Construction Industry Round Table, a national business trade association. He served on the American Institute of Architects (AIA) Large Firm Roundtable, composed of CEOs from large architectural and engineering firms working to advance the interests of practices working nationally and internationally.

MacLeamy was the keynote speaker at the Nordic BIM Academy’s buildingSMART conference in Copenhagen, Denmark, in November 2016. Nordic BIM Academy is Scandinavia’s largest conference devoted to OpenBIM. MacLeamy described his vision of BIM and collaboration in the AEC (architecture/engineering/construction) industry.

He is a Fellow of the American Institute of Architects and a Leadership in Energy and Environmental Design credentialed professional.

MacLeamy earned a Bachelor of Architecture and Master of Architecture in Urban Design from the University of Illinois at Urbana–Champaign.

MacLeamy and his wife, architect Jeanne MacLeamy, FAIA, live in Novato, California. American television journalist, author and speaker Elisabeth Leamy is their daughter. Their son, Patrick D. MacLeamy, is a licensed psychologist.