The house is on Fleming Rd and the fire was in a quarter of the roof of the house, a Fire and Emergency New Zealand spokesman said. The house is 30m by 30m large and firefighters were still at the scene working to put the blaze out, the spokesman said.
Emergency services were called at 8.15pm and police are also in attendance. It was not believed anyone was hurt and St John Ambulance had not been requested, he said.
There were four fire trucks and two water tankers on site and firefighters at the scene had requested a fire safety investigator to attend to determine the cause, the spokesman said.