At 6am, the Fire Service was called to a small fire in the garage of the two-storeyed College St house, which is being renovated by its owners, who do not live in the property.
Detective Sergeant Brett Roberts said it was the sixth fire at the house. The fires were believed to be the work of the same person or persons.
"It appears someone is specifically targeting this place," Det Sgt Roberts said.
He declined to comment on whether any accelerants were used in any of the fires.
While the arson attacks were a concern, the public had nothing to fear, he said.
"We would like to catch the person responsible sooner, rather than later."
The owners were stressed about the attacks, he said.
Anyone who sees anyone acting suspiciously should call 111.
