Property group Derwent London has won planning approval to turn its head office in the capital's Savile Row into an upmarket housing development.Derwent said Westminster City Council had granted consent for the re-development scheme on the site of its existing 42,300 sq ft headquarters building at 25 Savile Row W1, which it plans to vacate.The proposed new 58,000 sq ft building, designed by Stanton Williams Architects, comprises 29 apartments and 5,600 sq ft of shop and gallery space on the ground floor and six upper floors of homes together with car parking and ancillary facilities.In addition to the group's headquarters, the lower floors of the existing building are currently let to several tenants. Chief executive John Burns said: "Following the resolution to grant new planning consent to redevelop 25 Savile Row as high grade residential apartments, we are finalising our plans which include obtaining vacant possession and relocating our own offices."Derwent London shares rose 25p or 0.8% to 3060p at 12:20 in London.