HOK (formerly Hellmuth, Obata + Kassabaum) is a global architecture, interiors, engineering, planning and consulting firm. HOK is the largest U.S.-based architecture-engineering firm and the world's fourth-largest architectural firm. According to BD+C's 2010 Giants 300 report, HOK is among the nation's leading reconstruction design firms. HOK is also the country's leading design firm in terms of non-U.S. fee growth and the second-largest interior design firm. As of 2011, the firm maintains more than 1,800 professional staff across a global network of 25 offices and is active in all major architectural specialties. Its senior leaders are located in several different locations across the world.
HOK was established in St. Louis, Missouri, in 1955. The firm's name is derived from the surnames of its three founding partners: George Hellmuth, Gyo Obata and George Kassabaum, all graduates of the School of Architecture at Washington University in St. Louis.The practice's first building designs were schools in St. Louis suburbs, and St. Thomas Aquinas High School in Florissant was the first private/parochial school designed by the firm. Another prominent school they designed was the Saint Louis Priory School. By the mid-1960s, the firm was winning commissions across the United States and began to open additional offices, starting with San Francisco in 1966. By the 1970s the firm was operating internationally and in 1975 the firm was named as architect of the $3.5 billion King Saud University in Riyadh, at the time the single largest building project in the world.In 1983, HOK formed HOK Sport Venue Event, which became a leader in designing sport stadiums, arenas and convention centers. In January 2009, the Board of HOK Group, Inc. and managers of HOK Sports Facilities, LLC transferred ownership of HOK Sport Venue Event to leaders of that practice. The company is now known as Populous and is completely separate from HOK.HOK's first office outside the United States opened in Hong Kong in 1984 and HOK has continued to expand by opening additional offices in the United States and around the world and by acquiring other leading firms. In November 1994, HOK acquired CRSS Architects, Inc. based in Houston, Texas, adding offices in Houston and Atlanta.
In October 2008, HOK Canada was named one of "Canada's Top 100 Employers" by Mediacorp Canada Inc., and was featured in Maclean's newsmagazine. Later that month, HOK Canada was also named one of Greater Toronto's Top Employers, which was announced by the Toronto Star newspaper.In 2008, HOK opened an office in Mumbai, India.
HOK is an innovator in the building design industry and has greatly influenced the business of architecture. In 1983 HOK introduced HOK Draw, one of the first computer-aided drafting software products that specialized in conceptual architectural design. More recently, HOK has made a commitment to using Building Information Modeling (BIM) to streamline the design and construction process.HOK is a leader in sustainable design, commonly referred to as "green architecture." Professionals in the firm authored one of the industry's most respected resources on the topic, "The HOK Guidebook to Sustainable Design," originally published in 2000 by John Wiley & Sons. A second edition of the book was published in 2005. HOK currently has more than 900 LEED accredited professionals and 89 LEED certified projects.