Flames ripped through a Blackpool home destroying its lounge and a bedroom.
Fire fighters were called to the blaze on Devonshire Road, close to Laycock Gate, shortly before 7pm on Friday to reports of the house fire.
Fears were initially raised that there were people inside the home but after breaking down the door to search the property fire fighters found no-one.
The fire is now being treated as suspicious.
The blaze, which destroyed two rooms and caused smoke damage to the rest of the property, took six fire fighters around one hour to bring under control.
Crew manager Martin Dillon, from Bispham fire station, said: “An investigation is now underway into the cause of the fire. It was a decent size fire. Luckily no-one was home and smoke alarms, which had been fitted by Lancashire Fire and Rescue, did go off.”
Three fire engines, two from Forest Gate fire stationa nd one from Bispham fire station, attended the incident.
One man was treated at the scene, by paramedics, after suffering the effects of smoke inhalation.
Det Sgt Stuart Reid, from Blackpool CID, added: “Police are investigating this incident.”