A fire at a Rotorua panelbeaters workshop is thought to have started in one of the seven restored vehicles inside, four of which were classic cars.
The fire service forced entry into the Maisey Pl building around 8.30 last night where one vehicle was on fire.
Rotorua Fire senior station officer Richard Anastasi said although they contained the blaze to the car within 15 minutes it had the potential to be much worse.
"If it had been left another half and hour or so the whole building would of been ablaze," he said.
"We are conscious of fires in commercial buildings with the presence of chemicals and fuels etc."
The fire was contained to one car with no damage to the others.
Mr Anastasi said it highlighted the need for fire protection in all buildings.
The fire is being treated as accidental.