Specialist fire investigator Barry Gibson, of Dunedin, inspects a property in Peninsula Bay, Wanaka, extensively damaged by a fire. Photo by Lucy Ibbotson.
Firefighters were called to the blaze at 11.50pm after a resident out walking his dog spotted the flames. Wanaka Chief Fire Officer Ian Galloway said the fire was "well involved" by the time the brigade arrived.
Several contractors were working on the Forrest Heights house to finish its construction.
Mr Gibson said the fire was "accidental", the result of an ember lodging in the building's timber framing.
Mr Gibson said about one-third of the house was structurally damaged and at least half had smoke damage.
The owners of the property are believed to be from Christchurch, but the Otago Daily Times was unable to contact them.
