Scrapped plans to build a new headquarters cost Northumberland County Council £5.6m, new figures revealed.
Last year the Labour-run council was taken over by the Conservatives and the new administration axed the move from Morpeth to Ashington.
The authority's accounts for 2017/2018 revealed the figure included £1.4m compensation for the contractor.
A spokeswoman said money had to be spent on the Ashington plot to attract a new developer.
She said £2.1m was also spent on designing the new offices before the plan fell through.
"A further £2.1m is being spent on ongoing plot development works which we hope can be used by any new developer of the site," she said.
"The work undertaken by Arch and their consultants during the design and procurement stage for the building was part of the previous administration's capital budget and this spending is not something the current council did or would have sanctioned."
A spokesman for the opposition Labour group said: "After only one year, the full extent of Tory mismanagement is becoming clear."
The 2016 plan included building 200 houses, shops and a school in Morpeth although the developer pulled out in April last year citing concerns over "current market conditions".