Scaffold is currently up on the County Hall building in Norwich to protect visitors from falling tiles and the contract will include work to radically improve the building’s energy efficiency.

Carter will be working closely with NPS Property Consultants and the council to plan the work which will start in the spring of 2013 and last until 2015.

The work programme is being developed to reduce disruption to staff.

Mike Britch, Managing Director of NPS Property Consultants, said: “The most obvious sign that County Hall needs major maintenance is the scaffolding protecting staff and visitors from falling facing tiles, but in fact there are other less visible problems that have to be put right.

“Things such as leaks in the roof drainage system, hidden inside the walls, and problems with the sewers, drains, water and heating systems that are reaching the end of their lives.

“Movement in the building, although not an immediate risk, requires further investigation so that remedial action can be taken.

“It is a challenging but exciting project. We are fortunate to have, in R.G. Carter, a company that has experience in this sort of major project in a working office building. It is bound to be disruptive, but the planning now going on will keep this to a minimum.”

Energy efficincy improvements will include:

* Insulation added to the inside of exterior walls

* Secondary glazing to cut heat loss through the original bronze metal single-glazed windows

* Modern ventilation systems

* Efficient new heating

The Carter contract is the first of three phases of work on County Hall worth a total of £22m.

The second phase will focus on the north and south wings, while the third phase will see year on year maintenance continued to keep the building in good condition for a full 25 years.