The group remained there until 1951, when it joined with Westminster (formerly Yorkville Presbyterian) - Central (formerly Methodist) to become St. Andrew's United Church at 117 Bloor Street East.

The others were: Legislation, the Lieutenant-Governor's Residence; Education, the original home of Upper Canada College; and damnation, a tavern.

Around this time, 73 Simcoe Street became used as the postal address for the anti-Church Union group, the Presbyterian Church Association.

Later in the 20th century, the church's downtown location presented a challenge to St. Andrew's, since the area had become largely industrial and later one of the poorest in the city.

Eventually, the revival of the downtown core in the 1970s and 1980s began with the opening of the St. Andrew Subway Station at nearby University Avenue in 1963.

Further redevelopment of the area, including the addition of Roy Thomson Hall on the southwest corner of Simcoe and King Streets, transformed the neighbourhood, and the church is again prospering.

After acquiring air rights from new buildings in the area, there was an extensive rebuilding at the south end, including construction of a new condominium tower in which the congregation retained the first three floors.

The property (consisting of the manse and the church building) is designated under part IV of the Ontario Heritage Act since August 10, 1981.