The firm will produce a masterplan as the basis for two supplementary planning documents that will guide the future development of the site in Gosport and Fareham.
The site, known as Daedalus, will become a mixed-use development that will hopefully bring job opportunities in the aviation and marine sectors.
LDA Design partner John Phillipps said: "Daedalus has a fascinating heritage, having started as a seaplane base during the First World War and a major embarkation for the D-Day landings during the Second World War, which we are keen to ensure remains for generations to come."
"Our work includes understanding the history and character of the site and producing guidelines to retain its past, while catering for contemporary and future needs."
In March 2006, SEEDA acquired the 82.4ha site at Lee-on-Solent on the Gosport peninsula from the Ministry of Defence. The Maritime and Coastguard Agency purchased the remaining 106ha.
SEEDA development director Peter Cusdin said: "We hope that this exciting employment-led, mixed-use scheme will provide opportunities for jobs, investment and skills. This will bring benefits to both the local and wider area."
The full project team was assembled during early 2007.