Fraser Bond are the leading lettings and property management agents for One Seymour Street - London W1H. One Seymour Street, a development of 24 new homes in Marylebone, London W1, completed 2018. New Homes One, two and three bedroom apartments were originally for sale through Knight Frank. The new building has underground parking. The residents benefit from the 24-hour security and an opportunity for a membership to a private garden square. Developed by The Portman Estate. The site includes 6-16 Bryanston Street. History Former office building from the 1970s. 2015 June - Planning permission.