"There were direct flames coming out the front of the garage and the house - only about two metres away - had caught fire. The fire was only moments from going inside. We got there just in time," Mr Nielsen said.
The flames also had threatened a neighbouring home and a car parked at the nearby property.
Wooden window eaves on the neighbouring property had been in the direct line of the flames, he said.
Mr Nielsen said the blaze had erupted while the homeowner was at work and the likely cause of the fire was sparks from discarded fireplace ashes that had been left in a container in the garage.
The fire had severely damaged the building and a metal roller door, although there had been little other property consumed in the blaze.