A blaze broke out at a property in Bispham after a fire spread from the garden to the back of a house, say fire services.
Three engines were called out to the blaze on Sunny Bank Avenue at around 10.30pm on Wednesday August 16.
Firefighters initially believed that people were still inside the house and conducted a search using breathing apparatus.
They say that they quickly confirmed that nobody was inside the property.
Crews extinguished the blaze using two hose reels and a ventilation unit.
Watch Manager Andrew Jones said: "We arrived to find a well established fire at the rear of the property.
"Preliminary investigations indicated that the fire had spread to the property from a fence outside.
"The initial call said that people may have been in the building, so we conducted a search of the property but no one was found.
"The ground floor of the property was significantly damaged and there was smoke damage to the upstairs.
"We are currently working to establish a cause but at this stage it appears to be accidental.
"We would like to remind people to ensure that they have working smoke alarms - which the people in this property did.
"Smoke alarms can save lives and all properties should be fitted with them."
Nobody was injured during the incident.