Constable Robin Hutton, of Milton, said two fire crews were called to the Johnson St property after a shed containing building materials and supplies caught on fire about 6pm.
The flames were quickly contained by the fire crews and two appliances, he said.
It was "uncertain at this stage" whether the fire had been deliberately lit, Const Hutton said.
A fire safety inspector, accompanied by CIB detectives would investigate the cause of the blaze today, to determine whether it was suspicious, Const Hutton said.
The fire was the second "at this particular premises" in recent months, he said.