However, the curtain isn't quite ready to be raised as the client, Pegasus Theatre Trust, needs an additional £1.8 million of funding before work can begin.
The design of the 150-seat auditorium incorporates a copper-skinned two-storey foyer, which will be wrapped round the shell of the existing 50-year old theatre.
In addition to the foyer, FCB has incorporated a box office, a café, and rehearsal and dressing rooms.
FCB project architect Nick Brindley said: 'It's down to Pegasus Theatre Trust now. Let's hope they get more wealthy patrons.'
The project is being backed by The Arts Council of England, Oxford City Council and Oxfordshire County Council, and is expected to start on site in April next year.