One Campus Martius is a building located in downtown Detroit, Michigan. It began construction in 2000 and was finished in 2003. It has seventeen floors in total, fifteen above-ground, and two below-ground, and has 1,088,000 square feet (100,000 m2) of office space. The high-rise was built as an office building with a restaurant, retail units, space for Compuware and a fitness center, as well as an atrium. The building now has Rocket Mortgage, Microsoft, Meridian Health, Plante Moran and Compuware as its major tenants.