COS Chicago Office

New Chicago Office is now open!

COS General news

COS are excited to announce the opening our new US office, located in the Monadnock building, in Chicago. The Monadnock is a skyscraper located at 53 West Jackson Boulevard in the south Loop area of Chicago. The building was completed in 1893, and was at that time the largest office building in the world. It remains a building of great …