Work will begin on restoring the historic ‘pump room’ at the Crescent in Buxton in early November, according to developers.
They have been in talks with contractors for months in order to bridge a funding gap that developed as a result of escalating building costs.
Last November, the Heritage Lottery Fund stepped in with an extra £11.3 million to plug a funding shortfall and say all the money which has been awarded to the project since 2006 must be spent by the end of March 2019.
Trevor Osborne, from developers The Osborne Group, said: “We have been having to deal with ongoing difficulties with contractors but an early November start on the pump house is certainly what we are aiming to do.
“When completed it will be a lovely, wonderful public asset for Buxton as well as a place where visitors can find out about the history of both the Crescent and Buxton as a whole.”
The tender to manage the building as a hotel and spa was won in December 2003 and work was originally meant to be completed by 2007.
The work on the pump house would mark the first visible signs of progress for months on the £46 million development which has been plagued by delays due to legal difficulties and funding problems.
An HLF spokesman said: “We are working closely with Derbyshire County Council and High Peak Borough Council to support the project and understand that they are currently finalising negotiations with the main contractor.
“A separate contract for the repair of the Pump Room, which will eventually host the visitor centre, tearoom and heritage experience, is also being tendered shortly with work expected to start on site by November.”
The long-running project aims to bring the Grade I listed building back into public use for the first time since 1992.
When complete, the Crescent will be transformed into a 79-bedroom spa hotel, incorporating the neighbouring natural baths, a state-of-the-art thermal, natural mineral water spa and six specialist, boutique shops.
Coun Tony Kemp, executive councillor for regeneration at High Peak Borough Council, said: “We know that residents and businesses share our desire to see work to transform the iconic buildings of the Crescent and the Pump Room get underway so this is welcome news. The Crescent project is at the heart of our regeneration strategy and I hope this development provides some reassurance that all the parties concerned in this complex project are working hard to return these historic buildings to full and appropriate use.”