Council leaders in Aberdeen have said their new headquarters will not become "another Holyrood" with soaring costs.
Marischal College is one of Aberdeen's most famous buildings
The bill for moving staff into the historic Marischal College has almost doubled from £43m to just over £80m.
Deputy council leader Kevin Stewart told a special meeting of the full council that all contracts for building work would be fixed price.
Councillors decided on Marischal rather than moving to a greenfield site or redeveloping the existing HQ.
The council's move to Marischal College would pave the way for the demolition of the current headquarters at St Nicholas House.
Council officials said the refurbishment of Marischal would be more cost effective than bringing the St Nicholas House building up to standard.
The council's ruling Lib Dem and SNP administration said last week it was difficult to give guarantees about costs because the construction industry was going through a boom.
The opposition Labour group said it warned last year that costs would soar.
BBC Scotland last week revealed the cost of the project had gone up substantially.