Norfolk County Council has awarded a £14.2 million contract to finish the revamp of County Hall in Norwich to Mace Group.
The work will see the completion of the north tower, lower ground floor and basement areas, and will be completed by Mace Interiors, the interiors arm of the group.
A county council spokesman said: “Before we can move any more staff to County Hall, the north tower, lower ground floor and basement require essential renovations.
“These offices have had limited work done to them since they were constructed back in the 1960s. The work is essential to make sure they meet current safety regulations and are fit for purpose.
“This is the third and final stage of the County Hall development, which started in 2013, and will be funded by the capital budget already set aside for the repairs and maintenance of County Hall.”
It is expected the project will take 16 months to complete, and will include a full strip and fit-out, ventilation, heating and lighting upgrades, plus new layouts and open-plan areas, meeting rooms and a café.