"With the school holidays beginning, council is concerned that the building could become a magnet for children and it is important that we take steps to secure the property," Mr O'Shaughnessy said.
The Building Act allowed the council to erect the fence as it said it believe there was likely to be an immediate danger to the safety of the public "due to the state of the building".
"Mr Whittaker takes possession of the site in late January and then it will become his responsibility for ensuring there is sufficient deterrent for children and others from entering the building," Mr O'Shaughnessy said.
CCTV monitoring of the site would also help deter anyone from entering the building.