Kier will build a £14.7m enterprise centre at the new Horizon 120 Business and Innovation Park near Great Notley.
The three-storey centre will have offices, meeting rooms and conference/training facilities.
Work starts on site imminently and should be completed by summer 2022.
Braintree District Council director of growth Dominic Collins said: “The appointment of a main contractor is a major step forward for this project. Kier’s experience will help us create a modern and eco-friendly building which will generate opportunities for small businesses and create hundreds of jobs for local residents.”
Kier’s appointment to deliver the enterprise centre marks the second project it is delivering for Braintree District Council, after its appointment to deliver the £30m Victoria Square regeneration scheme, comprising 35 homes, a health centre, a Travelodge hotel, a new bus interchange, a café, new public realm and a twin-level car park.
Mark Dady, managing director at Kier Regional Building Eastern, said: “Our appointment to this scheme follows the ongoing success of our Victoria Square Regeneration project which is due to complete later this year. Both projects will greatly benefit Braintree by providing new facilities and employment opportunities for the community.”