Cassel House is a GRADE II LISTED BUILDING on Ham Common, London Borough of Richmond upon Thames which has been used as a therapeutic community since 1947. The facility, now run by the WLMH (NHS) Trust, only uses a small fraction of the existing buildings. We have looked at 2 scenarios for the site. One requires vacating the site completely and the provision of alternative premises closer to the 3 Boroughs that the Trust normally operates in. The second requires relocating to new purpose built premises within the existing grounds. The exercise required feasibility studies showing the sub-division of Cassel House into residential apartments, masterplanning additional dwellings within the historic grounds (in an attempt to put a market value on the site), looking at the suitability of alternative premises and the design of new facilities from a brief developed with the staff at Cassel House.