An outhouse caught fire at a house on Castle Hill, Conisbrough on Sunday.
The blaze started at around 1.30pm and was tackled by Doncaster, Edlington and Maltby firefighters.
The outhouse was being used as a utility room and is thought to have involved a tumble dryer.
Crews wearing breathing apparatus used hose reels to put out the blaze.
The cause of the fire is currently under investigation. The house was unoccupied at the time of the fire.