Hammel, Green and Abrahamson, commonly called HGA, is an architecture, engineering and planning firm that originated in Minnesota. It was founded in 1953 by Minnesotans Dick Hammel and Curt Green (Bruce Abrahamson joined in shortly thereafter). All three of HGAs founders were schooled in the Bauhaus tradition, which stressed a collaborative and inter-disciplinary approach to Modernism. They began their work designing K-12 school buildings. The firm later expanded into other areas, such as healthcare, corporate environments and higher education. They are currently one of the largest firms in Minnesota. HGA has expanded into eight national offices; Los Angeles, Sacramento, San Jose and San Francisco, CA; Milwaukee, WI; Minneapolis and Rochester, MN; and Washington, D.C.