the Annex. When the Fisher Building was constructed across Grand Boulevard in 1927, the two were connected with an underground pedestrian tunnel that also connects north to the New Center Building. They allow employees and visitors to traverse between the three buildings without going outdoors into inclement weather. Annex Building To the south of the main building is the five-story Annex which served as the original home of General Motors Research Laboratory. In 1930, the laboratories moved across Milwaukee Avenue to the Art Deco Argonaut Building. For many years after the Annex housed the Chevrolet Central Office. In 2009 when the Argonaut Building was sold, a fourth-floor pedestrian bridge connecting the two was removed and the Annex facade was restored. Renovation Between 2000 and 2002, the General Motors Building was thoroughly renovated to house the State of Michigan offices. Architect Eric J. Hill participated in the redevelopment which was headed by Albert Kahn and Associates, the original architects. In addition to upgrading existing systems, reconfiguring some spaces and redecorating, the project installed central air conditioning. When the building was first occupied, it was cooled in the warmer months by opening windows. Later, General Motors installed window units to cool various offices and work areas. During the renovation, large-scale systems replaced almost 1,900 window units that were left when GM vacated the structure. Photo gallery See also Fisher Building Henry Ford Hospital New Center, Detroit Penobscot Building Wayne State University List of National Historic Landmarks in Michigan National Register of Historic Places listings in Detroit References Further reading External links New Center Council Esmagazine.com: The Mechanical Modernization Of A Classical Icon Buildingphotos.com Skyscraper office buildings in Detroit Government buildings in Michigan General Motors facilities Headquarters in the United States National Historic Landmarks in Metro Detroit National Register of Historic Places in Detroit Office buildings completed in 1921 Neoclassical architecture in Michigan 1920 establishments in Michigan Albert Kahn (architect) buildings