Christian Candy has hired one of the UK’s best-known architects for the redevelopment of Sugar Quay near London’s Tower Bridge.

Lord Foster’s firm has been appointed to draw up proposals for a possible residential scheme of up to 230,000 sq ft on the site of the empty 110,000 sq ft office building on the north bank of the Thames.

Candy’s CPC Group bought the quay in February from the administrator KPMG for about £34 million — about the same as the debt that was owed on it to Lloyds Banking Group.

The site is a complex development prospect, however. The City of London does not encourage new homes except in areas of existing residential development, such as the Barbican or on the fringes of the Square Mile.

If the planning consent cannot be revised, CPC could proceed with the office plan.

The ownership structure of the property adds a further layer of complexity. The Fishmongers Company owns the freehold, and the site is held on an 80-year lease, which would need to be regeared for a complete redevelopment.

If this is not possible, the office building could be refurbished instead.

Candy told The Times: “We are working closely with the team at Foster + Partners to review the possibilities for the site, which could potentially be an existing office upgrade or redeveloped for commercial or residential use.”

The purchase marked CPC’s first property acquisition since 2008, when it bought Chelsea Barracks for £959 million with backing from Qatari Diar.