Fire crews from Waitati and Willowbank, in Dunedin, responded to the Station Rd fire about 2.45pm, a Fire and Emergency New Zealand spokesman said.
When crews arrived at the scene firefighters found a small fire in the roof, the spokesman said.
The fire was extinguished within 10 minutes of the first crew’s arrival, he said.
Firefighters then used a thermal imaging camera and a positive pressure ventilation fan to check the roof area for hot spots, and to ventilate the house, he said.
One occupant was checked at the scene for smoke inhalation, he said.
A St John spokeswoman said one patient was transferred to Dunedin Hospital but the injuries were minor.