The cost to repair and revamp Norfolk County Council's headquarters has increased to £64m - after the discovery of potentially dangerous defects added £5.5m more to the bill.
Work on County Hall started back in 2012, when £22m was set aside for structural repairs to the Martineau Lane building over the following 25 years.
That was triggered when concerns over masonry falling from the 1968-built council headquarters meant canopies were put up to protect staff.
But £10m was added to the first phase of work barely a year later as the true costs of what was needed emerged.
And, amid further work in the second phase to revamp the North Wing of the building, extra millions are being spent.
A decision was taken to add a further £5.5m to the contract which Mace Interiors Group was awarded for the North Wing work.
That came after what the council described as "urgent health and safety and building fabric issues" on the North Wing's facade, discovered during the work.
A council report revealed single skin external walls were being held in place by ties and had buckled over the years.
The report said there was a danger of "catastrophic failure", with a "very real risk of personal injury".
It meant walls had to be replaced, along with cladding - with "significant effort" needed to negotiate a design which satisfied the council's insurers in light of the role of cladding in the tragic Grenfell fire.
The extra £5.5m has come from the council's capital budget and means the bill for the County Hall work has climbed to £64m - £32m for phase one and £32m for the current phase.
The current phase of work, which has included improvements to the council chamber and meeting rooms used by councillors, had been due to be completed in August.
But the council said the Covid-19 pandemic has held up that work and "continues to influence progress".
The government announced last month that emergency legislation allowing for virtual council meetings will not be extended beyond May, which places a huge question mark over what will happen with the county council's annual general meeting if work is continuing on the council chamber.
When the original repairs were agreed, the demolition and rebuilding of County Hall was considered, but was ruled out.
And a county council spokesman said millions of pounds was being saved by closing and selling other council buildings.
A spokesperson said: "The refurbishment has run alongside a wider capital programme which has seen the closure and sale of several satellite offices.
"This will save the county council millions in running costs and secured a number of significant capital receipts.
"Most recently Carrow House was closed and sold which saw over 400 employees move their base to County Hall.
"The most recent works have addressed accessibility, safety and ventilation issues in the north wing, basement and civic area.
"We have also taken the opportunity to address long-standing issues with the infrastructure which have enhanced the energy performance of the building and brought the server room up to modern standards.
"During the refurbishment, urgent health and safety and building fabric issues have been uncovered which could not have been foreseen during the early design and tendering phases."
As well as the North Wing facade issues, there was a need for a new fire sprinkler system and a full replacement of a fragile roof over a meeting room.
But the cost is likely to increase yet further - because there is a proposal to fix the cladding on the South Wing of the building.
Steve Morphew, leader of the opposition Labour group at County Hall, said: "The way this was set up in the first place seemed to massively underestimate the costs, so there's questions about that.
"The timing of it means people are going to struggle to understand this is best time to be doing this and whether it is value for money."
Steffan Aquarone, leader of the Liberal Democrat group, said: "I am shocked at the total amount.
"If I was in charge at County Hall, I'd be putting the brakes on all but work which needs to be done for safety reasons to assess just what accommodation is needed for the council over the next 10 years."
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