A 1930’s office building behind Chatham House on St James’ Square was purchased by our client. The lower floors were kept as office space while the 3rd and 4th floors were converted to duplex apartments. The existing 5th floor was demolished and new double-height penthouse duplexes with terraces were designed to create unique and spectacular apartments for this prestigious address. Taking advantage of the two existing front doors, the internal circulation corridors were eliminated between the flats to maximise the rentable area. The three duplexes created were named after the historic owners of this property: Timbrell, Asgill and Alban.