A discarded cigarette is being considered as the cause of a fire at Mangatawa, near Papamoa last night.
Firefighters were called to Tareha Lane at 11.13pm after the fire ignited in house which had been converted into offices.
Mount Maunganui station officer Lindsay Nicol said the fire appeared to have started outside but spread inside and into the roofing.
''The thought is the cause of the fire may have been a discarded cigarette, as it started under the external deck,'' he said.
Although there was believed to be significant damage to the deck, a room and the roofing space, firefighters ''certainly saved most of the building'', Mr Nicol said.
