ST. LOUIS—A heralded architectural firm that has excelled in the justice design sector and beyond is celebrating seven decades of innovation and accomplishment.
Founded in St. Louis in 1955, HOK marks its 70th anniversary in 2025 as a global architecture, design and engineering firm with 26 offices and tens of thousands of built projects around the world.
Seventy years ago, George Hellmuth, Gyo Obata and George Kassabaum joined forces to create HOK. Though they came from different backgrounds and brought distinct skills, they shared a powerful vision. They wanted to build a practice where diverse talents could come together to enrich people’s lives through design.
“The whole reason HOK was started with Hellmuth, Kassabaum and myself was to do good design,” said Obata in a 2013 interview. “We believed in listening carefully to the client to understand the essence of the project and then make it a great design.”
The firm’s early work focused mainly on St. Louis with landmark projects such as completing the terminal design for St. Louis Lambert International Airport (work Obata and Hellmuth had begun at their previous firm, Hellmuth Yamasaki & Leinweber) and designing the Priory Chapel at Saint Louis Abbey and Southern Illinois University’s new Edwardsville campus.
HOK’s cofounders recognized the importance of diversifying the firm to win new work and continue to grow. They added new market types and disciplines—corporate, interior design, retail, civic—and in 1966 opened a second office in San Francisco. New HOK offices opened in 1973 in New York, Dallas and Washington, D.C.
Signature projects during this time included IBM’s Advanced Systems Development Laboratories in Los Gatos, California; The Galleria in Houston (one of the world’s first enclosed shopping malls); Dallas Fort Worth International Airport; the National Air and Space Museum in Washington, D.C.; and the Olympic Fieldhouse in Lake Placid, New York—the firm’s first sports project.
The period saw another milestone with Xerox’s Palo Alto Research Center, home to the greatest gathering of computer talent ever assembled, where teams developed the graphical user interface, laser printing and the first commercial mouse.
By the 1980s, HOK was winning international work, including King Khalid International Airport in Riyadh, Saudi Arabia, and was opening new offices in Hong Kong and London. The 1990s and early 2000s saw more international work, with offices opening in Canada, the United Arab Emirates and China.
Today HOK has 26 offices and boasts 11 unique market types and 10 different disciplines that include sustainable design, planning, experience design and landscape architecture in addition to core disciplines of architecture, interiors and engineering. The firm’s commitment to sustainability was underscored by its influential 2000 publication, The HOK Guidebook to Sustainable Design.
While the scale and scope of HOK’s work have evolved dramatically, its founding vision endures. “What’s remarkable about HOK is not just how we’ve grown since 1955, but that the principles set in place then are still being followed,” said HOK Co-CEO Susan Klumpp Williams, AIA. “Our longevity and success is based on our core strengths, which are our diversity of people, our diversity of markets and our diversity of locations. We continue to design spaces that exceed clients’ expectations and improve people’s lives. To quote George Kassabaum, ‘This firm is built on talented, dedicated people.’”
“The legacy of 70 years is extraordinary,,” added Co-CEO Eli Hoisington, AIA. “Our job now is to ensure the next 70 years are just as good. I’m optimistic they will be for two reasons: The vision put in place early at HOK, and the incredible people here now who will carry us into the future.”
HOK will celebrate its anniversary throughout 2025 with special events and a firmwide service program. Building on the firm’s tradition of community engagement—formalized in 2010 with the creation of HOK Impact—the “26/70” initiative will see each of HOK’s 26 studios volunteer a minimum of 70 hours toward a local community project or organization.
