In the wake of the Grenfell disaster, in which dozens of people died in a fire at the Grenfell Tower block in Kensington, London on June 14 this year, Sheffield City Council pledged to install sprinklers in every one of its 24 tower blocks.
The council says the work cannot begin until the interim report from the Grenfell Tower disaster has been published - although it is not yet known when that will be.
Once it has been published, the fire specialist hired by the council to advise them on sprinklers will consult with tenants and leaseholders on a 'block-by-block basis'.
A spokesman said: "We will procure the work after we have consulted with people and it could take approximately two years to complete all work.
"We estimate it could cost £3-4million to install sprinklers on all council tower blocks. However costs could increase as there is increased demand for sprinklers.
"We have had discussions with the Government (Department of Communities and Local Government) to ask for funding for the sprinklers. This has not been given to date and, unless Government makes an offer, the work will be funded from the Housing Revenue Account (rents) and leaseholder income."
A total of 20 of the council's 24 tower blocks have metal cladding, which the council say is fire proof because: 'the insulation is mineral and rock wool, with fire breaks at the floor and party walls. This creates a fire-proof box around each flat to the external structure to prevent the spread of fire to other flats'.
A spokesman said: "We carried out independent tests, following the Grenfell Tower disaster, to provide extra reassurance to people living in these tower blocks. These confirmed that the cladding is made from solid aluminium, and is safe."
And three of the council's tower blocks are brickwork-clad, which the local authority also deems to be safe.
The final tower block, Hanover, is waiting for cladding to be re-installed after its cladding was removed earlier this year because the Broomhall-based tower block failed the Department of Local Government’s sponsored fire safety tests (the BRE test).
The spokesman added: "We have also removed the insulation attached to the building because we are concerned that it could have been damaged when exposed to the weather.
"We are keeping people up to date with development at Hanover Tower via our website: www.sheffield.gov.uk/content/sheffield/home/council-housing/hanover-tower.html
"The cladding was originally put on the Hanover tower block in 2012 and was compliant with Building Regulations when it was installed.
"It cost £373,000 to remove the cladding and insulation."
"We do not have a final cost for a replacement system yet as we are waiting for the Grenfell Tower Fire Inquiry interim report to be published before we move to procure a replacement system."