Built in 1857 and designed by H.B. Sinclair, Cambridge City Hall is a fine example of Italianate public design and is an important heritage landmark. Over the years substantial changes have been made to the building, including a major renovation in 1965 by Peter Stokes and subsequent remodeling in 1990.

ERA was appointed on two separate projects for the building: The first involved the restoration of the exterior, which included a new slate roof and restoration of woodwork, eaves, masonry and windows; the second required the development and implementation of a Conservation Master Plan that related the Historic City Hall to a new administration building next door. The Master Plan included conservation of the building; removal of the stairway installed during the renovations by Peter Stokes; and relocation of the elevator to bring the interior closer to its original configuration and new exterior stairs.