The two fires were being treated as arson and although there were some similarities, from initial inquiries there was nothing yet to link them, Detective Sergeant Brett Roberts, of Dunedin, said.
The first fire, about 1am on Saturday, badly damaged a vacant house in Maitland St.
At 10pm on Monday, a vacant house was damaged by fire in Northumberland St, Northeast Valley.
Fire Safety Officer Barry Gibson said both fires started in furniture outside the front of the houses, both wooden villas of a similar design, and entered the roof sections of the houses in a similar spot.
It appeared the chairs had both been set on fire. He had not found an accelerant so far.
Det Sgt Roberts said the fires were of concern and it was lucky no-one was in the houses at the time.
For Paul Askey, the owner of the Northumberland St house, the two fires were too much of a coincidence.
It was disappointing and concerning that someone would set a house on fire not knowing if someone was inside.
"They obviously don't give a toss for anyone else's safety. Someone's just done it for a kick. We don't need this."
The house, which was insured, was being readied for new tenants.
The owners of the Maitland St house said it, too, was awaiting tenants. The house was insured.
Det Sgt Roberts asked anyone who saw anything suspicious or any movement in the areas before or after either fire to call Dunedin police.
