A neighbour alerted police at 6.50pm to the fact a home on a 100-acre property was alight on Razorback Road, between Marulan and Tallong.

“The house was almost entirely destroyed by fire,” RFS Southern Tablelands Zone Operational officer Daniel Osborne said. 

Four crews from Marulan and Tallong, comprising 15 firefighters, and one NSW Fire and Rescue unit attended. 

“When they arrived on the scene, they confirmed that the structure was fully on fire,” Mr Osborne said.

No one was home at the time. Police said the brick and tin home was a weekender owned by a Sydney family and was under renovation. 

One crew was at the scene early on Tuesday to mop up any hot spots.

Police and RFS are investigating the cause.