The house was unoccupied at the time of the blaze, which broke out between 7.30pm and 8pm.

The front rooms of the weatherboard house were gutted and the rest of the house extensively damaged by a combination of fire, smoke and water.

Arson chemists carried out an investigation at the weatherboard home in Bond St yesterday.

Ballarat Criminal Investigation Unit Detective Senior Constable Tony Euvrard said the cause of the fire would not be known until the chemists' report was completed.

"The fire chemist has still got to do his examination but it looks like the fire started in the front room of the house.

"There's no other indication about why it would be suspicious," Det Sen Const Euvrard said.

Resident Marcus Fletcher, 19, said he took his dog for a walk about 7.30pm, returning to find his home on fire.

"(At first) I thought it was the next door neighbours' house," Mr Fletcher said yesterday.

Mr Fletcher was the only member of his family at home on Sunday night. His mother, who did not wish to be interviewed yesterday, had rushed back from visiting a relative when she heard the news.

"It was just lucky no-one was in there," he said.

And while the family was insured, Mr Fletcher said the loss of belongings, especially memorabilia, would hit the family hard.

"We're a single parent family, we work hard for what we've got," he said.

Four trucks from Ballarat and Ballarat City brigades attended the blaze, which took about 20 minutes to bring under control.