HOK Group, Inc., formerly Hellmuth, Obata + Kassabaum, is an American design, architecture, engineering, and urban planning firm.

[20][21] The purchase of 360 Architecture in January 2015, a 200-person, Kansas City–based firm, gave the group capabilities in the design of stadiums, ballparks and arenas.

[22] That acquisition enabled HOK to launch a new global Sports, Recreation, and Entertainment design practice after the breakaway of Populous, and to open new offices in Kansas City and Columbus, Ohio.

[30] His team designed the Weather Prediction Center with a four-story waterfall to direct rainwater into bio-retention gardens; and a louvred sunlight system for a building used by the Office of the Chief Medical Examiner.

[31][32] HOK has worked with the Biomimicry Group, co-founded by Janine Benyus, since 2008, which directs designers to use natural models in solving problems such as precipitation capture.

[33][34] In 2010 they collaborated with the energy and daylight consultancy, The Weidt Group, to complete Net Zero Court, a zero-emissions class A commercial office building in St.

[37][38] Their design for the Boston Consulting Group HQ in Toronto in 2022, uses principles of wellness-informed architecture, to maximise natural light and encouraging standing, for which it won WELL Platinum Certification from WELL Building Standard accreditation body.