�We reckon it will cost about $120,000, but because of that it will have to go to tender,� council chief executive John Merrick said.
On March 26, the council sent its order to Mrs Oswal�s Sydney lawyers to demolish the mansion on 6582sq m that has been incomplete since she and her husband Panjak Oswal left Australia in 2011, after spending about $13.5 million on the building.
On December 16, the council declared the mansion unfit for human occupation after an inspection found no external waterproofing, lighting, food preparation areas, toilets or laundry, power or gas and some staircases without balustrades.
Another inspection found no safety work had been done by March 13.
The council has asked Mrs Oswal to board up ground floor access, fill in an underground pump house, truck away rubble and mow weeds, after it spent up to $50,000 on fencing, securing and patrolling the mansion.
It does not expect to recover the cost in any sale of the mansion�s land.
After the council agreed on the order two weeks ago, Mrs Oswal�s Sydney lawyer Rebekah Giles said her client wanted to complete the mansion. Any demolition cost was better spent on improving the building�s safety and contractors would do the safety work.
However, Mrs Oswal has no building licence and she allegedly still owes the council about $96,000 in rates, after paying about $58,000 on December 30.
Mr Merrick said the only known contractor was a man in the mansion who said he was getting quotes when seen by passing council staff about six weeks ago.
The Council expects a reply to the demolition order �at the last minute� and Mrs Oswal to appeal to the State Administrative Tribunal within 21 day of the order being made.