The bedroom and porch of a house in Manuherikia Rd near Alexandra were destroyed and the rest of the house badly smoke-damaged by fire last night.
About 28 fire personnel in three fire appliances fought the blaze, which Chief Fire Officer Russell Anderson said was reported by a young girl who was at home alone in the house.
She told the fire service when she met them at the bottom of the drive she had been watching television when she heard a window break and realised there was a fire on the front porch.
She then discovered the fire had gutted a bedroom off the front porch and burned through the ceiling and into the roof.
It took the fire brigade about an hour to bring the fire under control.
Police did not want to make any comment last night about the girl. It is believed she went to stay with relatives.