One of the new councils is planning to rent out sections of two its buildings.
Following the merger of the Antrim and Newtownabbey councils, the new body was left with two modern headquarters buildings.
Mossley Mill was converted from a 19th century linen mill around five years ago to serve as the headquarters of the former Newtownabbey Council.
The Antrim Civic centre is also a modern building and was the home to the former Antrim Council.
However, now the two buildings are owned by the one council, areas within both are currently empty. The council names Antrim Civic centre as its headquarters on its website, but this week it has advertised space at both it and Mossley Mill for rent.
A council spokeswoman said: "Currently, the ground and lower ground West Wing of Mossley Mill, along with two rooms in Antrim Civic Centre, are being marketed for rental by Osborne King."
"An area within Mossley Mill had previously been leased by Capita Managed IT Solutions. The rental of these areas will not affect the location of staff, who will continue to work in their existing office space. Renting these areas will provide additional income for the council, which can be utilised for the benefit of the local community."