Repairs to dangerous concrete at Medway Council’s headquarters could cost £20 million.

The council’s main offices at Gun Wharf, Chatham, closed last October after dangerous concrete – known as reinforced autoclaved aerated concrete (RAAC) – was found in the roof.

It has now been revealed that repairs could cost an eye-watering £20 million.

Work includes a replacement roof, thermal insulation and essential internal repairs.

Although a timeline is not yet known, the repairs could take up to three years from the approval of funding.

Options such as building a new HQ or leasing a property are off the table.

However, buying a new HQ is still an option – although it is not being recommended by council officers.

As Gun Wharf is a Grade II-listed building, the council will need to consult English Heritage during the repairs.

The report says the council’s repayment would cost £56,555,000, including interest of £36,555,000, based on an interest rate of 6.5%.

Councillors will make a decision at a Cabinet meeting next Tuesday (13 February).

Cllr Vince Maple, leader of Medway Council, previously said: “It is regrettable that we have had to temporarily close our main offices at Gun Wharf in Chatham.

“We are not alone in finding ourselves in this unfortunate position, with other councils and public buildings, such as hospitals and theatres, across Kent and the rest of the country working through the unknowns of rectifying this type of concrete being used in older buildings.”