The fire broke out on the second floor of the home, on White Way, Casula, just before 10pm and quickly expanded into the roof before overwhelming the entire property.
When emergency crews arrived on the scene, huge flames and plumes of smoke had covered the entire top floor.
It took more than 20 firefighters and over three hours to eventually extinguish the blaze.
“There was significant damage to the property,” a spokesman for Fire and Rescue NSW told 9News.
“I could say with some confidence that that house has been totally lost.”
The fire was able to be contained before spreading to neighbouring properties.
While there have been no reported injuries, authorities are working today to establish the cause of the blaze.