In 1983, the City's Administration moved into 55 avenue Dupras, following its purchase of the building formerly occupied by Burroughs Wellcome, a pharmaceutical company that relocated to a new plant in Kirkland in the West Island. 

On January 1, 2002, City Hall on Avenue Dupras became the "Office of the Borough of LaSalle of Ville de Montréal", commonly referred to as the "Borough Office of LaSalle", following the mergers of all the municipalities on the island of Montréal. At the time of a referendum on a possible demerger, LaSalle residents decided to remain within Montréal.