Gerald A. “Gerry” Rauenhorst, 86, a design-build pioneer and founder of The Opus Group, which became one of the largest U.S. builder-developers before being hit by financial troubles in the recession, died on April 24 in Edina, Minn., after a long illness.

Rauenhorst, a civil engineer, launched an eponymous construction company in 1953 that later become The Opus Group, a Minneapolis-based commercial real estate developer that provides turnkey A/E/C services through three subsidiaries in nine U.S. offices.

Opus has completed 2,300 projects totaling 227 million sq. ft., including the 56-story Capella Tower in downtown Minneapolis, the 1.6-million-sq-ft. Best Buy corporate campus in Richfield, Minn. and University of Minnesota’s 10,000-seat Mariucci Arena.

Rauenhorst was an early proponent of an integrated project approach, later known as design-build, which pushed company billings to $2.5 billion annually.

Rauenhorst was awarded a Design-Build Institute of America lifetime achievement award before he retired in 2007.

ENR ranked Opus as the country’s eight biggest design-build contractor in 2007; however, the company was hard hit by the recession when three regional subsidiaries filed for 2008 bankruptcy.

Opus recovered, settling most internal and external lawsuits, and reemerging slimmed-down with ownership still intact.

Although Rauenhorst retired from daily company operations in 2007, transferring control to a family trust, two children remain on the Opus board of directors.