Carillion has started work on the first of four deals worth £75m at the Royal Navy Air Station at Yeovilton.
Carillion has four contracts for work at the station, including training and office facilities, worth a total of £75m.
RNAS Yeovilton will become the home to the new Wildcat helicopters of the British Army and Royal Navy, with Army regiments moving from Gütersloh in Germany, and Yorkshire to the Navy Air Station.
Carillion will will deliver new accommodation, sports and medical facilities at the Somerset air station. Works start this month and the project is set to be completed in November 2016.
Richard Lumby, managing director Carillion Defence, said: “We are delighted to have secured these contracts which will see Carillion deliver vital facilities for both the Royal Navy and Army and the men and women who will be based at RNAS Yeovilton.
“This project will not only see Carillion transform the base but also create local jobs, including apprenticeships, and work with local suppliers as part of our commitment to bring lasting benefits to our customers and the communities in which we work.”