People in neighbouring properties were evacuated and nobody was injured.
Dawson Mutu lives across the road from the properties and was first to see the flames in the property's front room.
The fire escalated quickly and before the fire department arrived, the blaze was moving across the roads, he said.
"If the fire brigade didn't get there when they did, we could all be in dire straits here on the other side of the road."
Flames reached 10 metres in the air and the billowing smoke was thick.
Mr Mutu said it was terrifying to see, especially because he had a four year old daughter and a two-week-old son in his home.
Another neighbour had called police after they saw people behaving suspiciously around the area and they arrived quickly to the scene, Mr Mutu said.
Police told Mr Mutu they were speaking with people in relation to the blaze.
Another neighbour, Mark Burns said it was "the most major fire I've ever seen".
"Intense heat and explosions and I couldn't get nearer than about 50m from the place."
He heard an explosion from his home and saw a big glow, which drew him out to see what was happening.
The main house was gutted and the neighbouring houses were "severely damaged", he said.
"I would say that all three would have to come down."
Another neighbour, who didn't want to be named said she heard some explosions. She said the blaze was enormous and expanded very quickly.
"It was very scary."
Fire Service risk management officer Russell Dickson said the house where the blaze started had been "totally destroyed" in the fire.
"It then affected the other houses. Fortunately our guys got there in the nick of time to cut the fire off and prevent more major damage.
"Both houses have been damaged, but not as severely as one would expect in another five minutes."
Mr Dickson said he was investigating whether an accelerant had been used.
"It's been a rapid fire and we've got to find out why."
The house had been under renovation at the time.
"The house was totally stripped out - it was just bare walls, studs and things like that."
Mr Dickson said the house was now a shell which needed to be bulldozed.
"Nothing's saved - it's totally destroyed, and I mean totally."
Fifteen fire trucks and 60 firefighters battled the fire.
