Keith Williams has seen off major opposition to land the RIBA-organised competition to design a new museum in Chichester, West Sussex.
The practice fought off competition from Panter Hudspith, Tony Fretton Architects, Caruso St John, van Heyningen and Haward, and Jamie Fobert to pick up the commission.
The site of the development, close to the city's Cathedral, is currently a car park, but contains the remains of the Roman baths of the city of Noviomagnus Regni.
These baths will be a permanent exhibit, forming part of the exhibition that will explore the history of Chichester and its district.
The project will also include a residential development on part of the site, which Williams will also design, in order to fund the scheme.
Keith Williams said: 'We are delighted to have come out ahead of a very strong field to win this prestigious project.
'We are looking forward to developing our concepts with Chichester District Council and its project manager RLF for a fine new museum in this historic city,' he added.
Development work has started on the £6.6 million project. It is hoped that the new building will be opened in 2010.by Ed Dorrell