A special meeting will be held next Monday at the City Council's new offices at Crown Square.
The controversial move to the new location on the Monivea Road, which will take place next year, has been criticised by both council staff and councillors.
The €45m deal was approved by councillors in 2022, but valuations just last month show an €8m drop in value.
However, officials say the move remains the most cost-effective solution to house current and growing staff numbers.
Images of the intended interior have been revealed, and a tender for its fit-out has recently gone to market.
The building will feature modern facilities, including upgraded AV systems and better public access.
A public information campaign is planned ahead of the 2026 move, alongside ongoing staff and union engagement.
