A family escaped a blaze in their two-storey Greymouth home.
The fire service was called to the house on Wickes St, Cobden, at 10.15pm Sunday, after reports of smoke coming from the roof.
Initial reports were that there were people in the house.
Upon arrival at the scene, the house was fully ablaze, a fire communications spokesman said.
All occupants were out of the house and uninjured.
Crews from Cobden, Greymouth and Runanga attended the fire, which has now been extinguished.
The damage was extensive, the spokesman said.
He said a fire investigator will be at the scene in the morning, and the cause of the blaze is unknown.
Two crews remain at the address to dampen hot spots.