Christchurch fire crews were kept busy last night with two serious blazes across the city.
Southern fire communications shift manager Brent Dunn said a house fire in Richmond's Harvey Crescent at 11.40pm extensively damaged a two-storey home.
No one was in the house at the time, Mr Dunn said.
"Investigators are responding now to investigate the cause."
The fire was being treated as suspicious until deemed otherwise, he said.