Fraser Bond are the leading lettings and property management agents for Thirty Casson Square - London SE1. Thirty Casson Square is a 29-storey residential building in the Southbank Place development in London SE1. New Homes: The building contains studios, 1, 2 and 3-bedroom apartments, together with a collection of signature penthouses. 4-bedroom 638.9m2/6,875 sq ft duplex penthouse on levels 28 and 29. Availability, floor plans and brochure are available here. Contemporary interiors by world-class design house Johnson Naylor. Show home by Portia Fox. The views on offer are some of the best in the.