[1] However, after the enlarged Metropolitan Borough of Westminster was formed in 1900,[2] civic leaders decided the Caxton Street building was inadequate for their needs, and decided to find larger facilities; they selected an existing building in Charing Cross Road,[3][4] which re-opened as "Westminster City Hall" on 29 May 1902.

[4] In the early 1960s, in anticipation of the impending further enlargement of the council's area, civic leaders again decided they needed larger facilities; the site they selected formed part of a larger development by Land Securities on a site previously occupied by Prince's Mansions in Victoria Street.

[5][a] The proposed development was a 76.20 metres (250.0 ft) high,[8] 20-storey glass tower, designed by Burnet Tait & Partners in the modern style, which was built by Taylor Woodrow Construction.

[9] The enlarged City of Westminster was formed in March 1965, shortly before the completion of the new town hall in April 1965.

[10] Initially, Westminster City Council only used the 20th floor, but gradually expanded to take the whole building.