Art Gensler, the American architect, interior designer and founder of global architecture firm Gensler, has passed away at the age of 85 after a long illness. The founder of the world's largest architecture firm died in his sleep at his family home in Mill Valley, Marin County, reported the San Franciso Chronicle.

Gensler founded his practice in San Francisco in 1965 with the late Drue Gensler, his wife, and James Follett. Today the firm operates in 50 countries around the world and has an annual revenue of $1.5 billion. Despite being diagnosed with lung disease 18 months ago, Gensler had continued to work for his practice and still had a full calendar of meetings scheduled when he died.

"My dad was a regular guy, respectful and friendly and never pompous," his son David Gensler said. "He loved serving clients through the power of design."

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