A whopping £20 million could be borrowed to deal with crumbling concrete at a council headquarters to make the building fit for use for the next 40 years.

Medway Council’s Gun Wharf will get the huge investment to deal with reinforced autoclaved aerated concrete (RAAC), council papers say.

A report that will be discussed at a cabinet meeting on Tuesday, February 13 will provide options to members about what to do with the authority’s HQ which has been largely closed due to RAAC being discovered.

The concrete became national news in September last year when schools across the country were closed because of fears that buildings might be unsafe.

Parts of Gun Wharf were found to have RAAC in October, leaving it with limited available space, forcing many council staff to work remotely.

The report released on Monday, February 5 listed a number of possible options for dealing with the Grade II-listed building in Dock Road, Chatham.

The option recommended by officers is to borrow £20 million to deal with the problems and to renovate the building, bringing it up to date and making improvements that will help it service the Towns for another 40 years.

Among the alternatives suggested was that Gun Wharf be sold off and a new HQ found, however the report says this is not a cost-effective option.

The report also says officers looked into the viability of building or leasing a new main office for the council and even doing nothing, continuing to operate with reduced capacity at the current site - however these were all dismissed as being economically unsound.

Based on current interest rates of 6.5%, the £20 million borrowed would add £1,413,875 to the authority’s annual bills for the next 40 years - making the total cost including interest £56,555,000.

Despite the high price tag, officers say this is still the most cost-effective option that has been explored.

One of the difficulties around renovation of the building is dealing with its Grade II listing, which can limit the extent of work which can be done.

The report will go to cabinet next week to be discussed by councillors and, if the recommended option is approved, consultation about the exact way work can be completed will begin.

Even if agreed next week, work to get Gun Wharf back into operation is expected to take several years.