The Fourth & William Parking Structure is downtown Ann Arbor’s largest parking structure. Originally built in 1966 as a four-level, cast-in-place concrete pan joist structure, it was expanded vertically in 1981 with three levels of structural steel and cast-in-place concrete slabs. The initial steel expansion was built with weathering steel with added steel frames to laterally brace the building.

Given the demands placed on the structure by the successful growth downtown, as well as the many attractions in the Main Street area, the Ann Arbor Downtown Development Authority retained WGI to further increase downtown’s parking capacity by vertically expanding the Fourth & William Parking Structure by one additional level.

Planning for the expansion began in 2000, and in the years leading up to the expansion, WGI restored and upgraded the architecture of the facility. Renovations included new canopies at pedestrian openings, pedestrian walkways, bicycle parking areas, accent painting, new lighting, functional improvements, a new parking office, restroom, signage and an expansion of the stair tower window openings.

WGI has completed several more cycles of maintenance and repair at the facility, and in 2014, WGI oversaw the replacement of the stairs and elevators.

Project Highlights

• Addition of one level of parking for a total of seven
• Steel framing with cast-in-place concrete pan joist system
• Vertical expansion created 142 additional parking spaces for a total capacity of 1,012 spaces
• Added new express ramp from grade to Level 2