Hot ashes inside a vacuum cleaner were believed to have caused the fire in the living room of the Beresford St, Wakari home at 2.30pm.
Roslyn Fire Station station officer Scott Lindsay said the house's sole occupant at the time of the fire was awoken by a smoke alarm.
"It alerted her to the fire and she evacuated the house."
The woman was shaken and received first aid at the scene for smoke inhalation. A poodle was rescued from the property.
The fire highlighted the importance of smoke alarms.
"If it had not activated, we would more than likely be dealing with a fatality," Mr Lindsay said.
It also served as a reminder for people "not to vacuum ashes, as although they may appear cold they can stay warm for some time".
People were advised to leave them in an ash tin for at least 48 hours before disposing of them, he said.
