Restoring the landmark building, currently closed due to safety issues discovered in 2020, was considered the best value option for the council’s accommodation needs.

Despite an initial cost projection of £45m, the council stuck with Sisk, which signed a pre-construction service agreement in August.

Designed by architect Hawkins\Brown, the project will provide the 66-year-old headquarters building on Wood Green High Road with a new annexe, offices, and restored civic spaces.

A three-storey office block will be constructed on the car park to the rear of the site, linked to the revamped civic centre by a two-storey block

The revamp, which will also upgrade the building’s energy performance, will see the building’s extensive precast concrete panels replaced with glass-reinforced concrete of the same colour.

The building was the first civic centre of its size to be built after the Second World War and was listed in 2018.

Cllr Ruth Gordon, Cabinet Member for Placemaking and Local Economy, said: “Residents will understandably ask whether the council can afford to continue with this project given the funding challenges it faces.

“The business case, which we have continually retested, makes it clear this scheme offers the best value for money of all the options available.

“Doing nothing is not an option and even that, given our responsibility to the listed building, would cost millions and not bring the site back into civic use.”