Under his leadership, HOK grew into a global design firm while developing the collaborative culture that still defines it today.
Jerome J. “Jerry” Sincoff, FAIA, whose leadership helped drive HOK’s growth from a significant U.S. architecture firm into an international design leader, died Dec. 18, 2024. He was 91.
Sincoff was a lifelong St. Louis resident. He graduated from University City High School in 1951, earned his architecture degree from Washington University in St. Louis in 1956 and then served in the Army Air Defense Command. He joined HOK in 1962 after interviewing with founding partner Gyo Obata. His project management skills on the Southern Illinois University-Edwardsville campus project quickly caught the attention of another founding partner, George Kassabaum.
Sincoff led some of HOK’s most complex, largest-scale projects. These included the Smithsonian’s National Air and Space Museum in Washington, D.C.; Mobil Corporation’s World Headquarters in Fairfax, Virginia; the BP America Building in Cleveland; the Bristol-Myers Squibb Headquarters and Research Campus in Lawrenceville, New Jersey; and the 1901 Avenue of the Stars office building in Los Angeles. Closer to home, his projects in St. Louis included One Bell Corporate Center; the Nestlé Purina PetCare Company headquarters; the Edward Jones building; and the preservation and renovation of St. Louis Union Station.
Clockwise: Air and Space Museum (Wash. D.C.); Union Station renovation (St. Louis); BP America Building (Cleveland); Mobil Corporation HQ (Fairfax, Va.); Bristol-Myers Squibb HQ (New Jersey).
Following Kassabaum’s unexpected death in 1982, Sincoff stepped into HOK’s leadership as vice chairman. In 1990, Sincoff became the first person not named Hellmuth, Obata or Kassabaum to lead the firm, becoming CEO when Obata stepped down to serve as chairman.
During Sincoff’s decade as CEO from 1990-2000, HOK grew dramatically, expanding from 14 to 20 offices worldwide and nearly doubling its workforce to 1,600 people, with new studios in Houston, Atlanta, Chicago, London, Toronto and Dubai. He led the formation of HOK’s market-focused, global specialty practices in areas like sports, aviation and healthcare, while publishing “OneFirm Guidelines” to encourage teamwork across offices. His leadership philosophy centered on building enduring client relationships focused on long-term success rather than just completing individual projects.
Beyond physical expansion, Sincoff shaped HOK’s organizational culture by creating internal professional development programs and championing sustainable design as a core value.
“Jerry approached every challenge with optimism and warmth,” said HOK Co-CEO Susan Klumpp Williams, AIA, LEED AP. “He had the unique ability to develop a clear vision for the firm and then bring everyone together to achieve it.”
His leadership style extended beyond strategy to personal connections. He made a point of calling individual employees on significant work anniversaries—a practice that left lasting impressions. “Being the recipient of one of those calls from Jerry made an impression on me that I never forgot,” Klumpp Williams recalled.
After stepping aside as CEO in 2000, Sincoff spent a transitional year as chairman of HOK. He then remained at HOK as an advisor to the firm’s corporate market practice.
Left to right: Jerry Sincoff, Gyo Obata and King Graf (HOK’s former marketing director) in the early 1990s.
Sincoff remained involved with Washington University throughout his life. In 2004, he was one of seven recipients of the University’s Distinguished Alumni Award, and he earned the College of Architecture’s Dean’s Medal for service in 1999 and a Distinguished Alumni Award in 1997. He sat on several boards—including the Board of Trustees, Alumni Board of Governors and School of Architecture National Council—before stepping in as dean of both the College of Architecture and the Graduate School of Architecture & Urban Design in 2005 and 2006. Together with his wife Suzanne, he created a scholarship fund to support future architects.
Sincoff helped create the AIA’s Large Firm Roundtable and was the first architect to lead the Construction Industry Round Table. He was active in the National Academy of Sciences research council and National Building Research Board. In St. Louis, he took leadership roles at the Saint Louis Art Museum—as both trustee and commission president—while maintaining longtime membership in the United Hebrew Congregation in Chesterfield.
He was the son of the late Elma and the late Maurice Sincoff; beloved husband of Suzanne Sincoff; father of Julie Jampel (the late Jeffrey), Robert Sincoff (Diane) and Steven Sincoff (Whitney); stepfather of Biron Valier (Julie Hallett) and Jennifer Drury (Brian); grandfather of Henry Valier, Ethan Jampel, Johnny Valier, Emily Sincoff, Alex Sincoff, Miles Drury and Lucas Drury; step-grandfather of Jacob Jampel and Sophie Jampel; brother of Theodore Sincoff (the late Christine); and former spouse of Judith Sincoff.
A private graveside service took place on Dec. 23 at United Hebrew Cemetery in St. Louis. The family requests that memorial contributions be made to either the Saint Louis Art Museum, 1 Fine Arts Drive, St. Louis, MO 63110 or to Washington University and directed to Graduate Architecture Scholarships. Checks should be made payable to Washington University and sent to: MSC 1082-414-2555, Washington University, One Brookings Drive, St. Louis, MO 63130-9989.