The Albert Street fire left the home irreparably damaged.

Horsham Fire Brigade attended the fire about 11.55pm.

A mother and her five children escaped the burning house uninjured.

Operations officer Ian Day said the cause of the fire was still unknown.

Forensic investigators from Melbourne will attend the scene to determine the cause of the fire.

Mr Day said due to the damage caused by the fire, the home could not be salvaged.

Incident controller First Lieutenant John St Clair said the woman and her children were safely out of the house when fire crews arrived.

"We received a call about 11.55pm on Thursday about a smoke alarm," he said.

"No-one was injured and the family will receive emergency accommodation."

Lt St Clair said four fire trucks and 15 fire crew attended the fire.

Ambulance officers treated the occupants at the scene.

Powercor disconnected power to the house and Horsham police also attended.