Renovations at Diss Corn Hall are set to be complete for January 2017 after the construction contract was awarded to a Norwich-based company.
Pentaco Construction Limited was one of four firms that took part in the competitive tender for the Corn Hall work, which will cost almost £1.6m, and will begin work in mid-January.
Working to designs byHudson Architects, the project will restore and upgrade the original Corn Hall, Waveney Room and Council Chamber, adding a modern two-storey extension at the rear to provide box office, foyer, bar, gallery and exhibition areas.
The Corn Hall has been stripped back of all of its furnishings and equipment since closing in the summer, while the majority of the asbestos has been removed.
The work is part of the £3 million Heritage Triangle project.