Whanganui firefighters have put out a blaze on top of a two-storey home in St John's Hill.
Two fire trucks were deployed to the Brassey Rd property at about 8.15am on Monday.
Station officer Bryan Coskerie said the fire was escalating when they arrived.
"It was just ready to destroy the house, so we arrived in a timely manner to prevent major damage," he said.
"At this stage the fire damage is confined to what appears to be a kitchen area. There were no persons present when the fire started."
Emergency services were called by residents from a neighbouring property.
A fire investigator will attend the scene to ascertain the cause of the fire, which Coskerie said did not seem suspicious and may be attributed to an appliance.