A cigarette caused a fire which started on a balcony deck then spread to the lounge area of an unoccupied home in Bellevue.
Three fire crews responded to a 111 call received at 2.18pm on Christmas Day after a fire started near a barbecue and broke through a window, spreading inside to the lounge.
Neighbours of the unoccupied home had done a "good job" containing the fire with a garden hose until fire crews arrived, Tauranga senior station officer Len Sabin earlier said.
Apart from some smoke damage, there was only minor fire damage to the lounge, he said.
Fire Service investigator Stuart Booten said this was a potential tragedy waiting to happen.
"The cause of the fire was a discarded cigarette. Over the years discarded cigarettes have been the cause of many fires, some resulting in properties being completely destroyed.
"It is really fortunate in this case a nearby resident acted so promptly. It's really important that people ensure they discard their ashes and butts safely," he said.
Booten said if people were going to smoke outside they needed to ensure they had a metal bin with sand in it close by for their butts.