The incident happened at around 10.45pm on Saturday in Cameron Park.
A 62-year-old woman had left her home earlier that day, leaving the property unoccupied.
Police and fire service were called in the evening when members of the public saw the house on fire.
A number of items were stolen from the property before the fire was started and detectives are now keen to speak to anyone who can help with inquiries.
Officers are particularly keen to trace a male who was seen in the area around the time of this incident.
He is described as white, mid to late 20s, 5ft 8in with a stocky build. He was wearing a white baseball cap, dark clothing and was riding a mountain bike.
Detective Sergeant Heather Powell said: "Fortunately no-one was within the property when it was set alight and so there were no injuries as a result of this incident.
"Nevertheless, we are treating this extremely seriously and are eager to speak with anyone who was in the area around 10.45pm on Saturday who remembers seeing anything suspicious."