The police said they were investigating how a house fire started in Kambah on Thursday afternoon.
The two-storey home was gutted and empty except for a dog which had to be rescued, the Emergency Services Agency said.
A spokesperson for ACT Policing said on Friday morning that the cause was unknown and officers would conduct an investigation.
Emergency services were called to the scene late on Thursday afternoon when flames were coming from the roof of the property.
By 7pm fire crews had searched the property twice and found no people inside it but a dog which had to be rescued by a professional dog handler, the ESA said.
The fire was brought under control but some firefighters remained on the scene to put out hot spots. No injuries were reported.
A family living next door evacuated their house when they noticed smoke and flames coming from the property.
Eessu Witcombe was at home with her seven children, aged from four to 17.
"The whole front of the house was on fire and I said, 'Get all the kids out'," Ms Witcombe said.
Her son, Haqu, 17, was watering down a shed fence with a hose before firefighters arrived.
Ms Witcome said she heard small explosions from the house and called out multiple times to see if anyone was in there.
As soon as the explosions started, she said to her son: "Drop the hose, we're out".
The heat of the fire was ferocious and it was a terrifying experience, she said. They believe the fire began about 4pm.
Rachael and Izzy Mendoza saw the house on fire from their home about 100 metres away across the park.
They rang triple 0 and ran to help.
"By the time we got to the gate, flames were definitely coming out of the roof. It was crazy," Mr Mendonza said.
Thick smoke filled the street as many neighbours watched on.
Multiple fire appliances were at the front and back of the property and fire crews wore breathing apparatus.