Police are investigating a blaze which destroyed the roof of a new home being built in Poulton.
The roof of the building on Little Poulton Lane was set alight on Wednesday shortly before 4am.
Lancashire Police has started an arson investigation into the incident.
A spokesman: “We responded to reports of an arson incident at 4am on Wednesday.
“The building has been quite substantially damaged following the fire.
“We have opened an arson investigation however there have been no arrests currently.”
The house was being constucted in partnership with building consultancy Carter-Zub.
Harry Carter, the owner of the company, said: “We are absolutely devastated for the current owners.
“This sort of think makes such an impact on people’s lives and we can’t understand why anyone would decide to do it.
“The owner has been working really hard on the house and has been there every day and it’s such a shame this has happened.
“I hope the people come forward that have done this or somebody who knows anything about it.”
A spokesman for Lancashire Fire and Rescue said: “The cause of the fire is believed to be deliberate and an investigation will take place.
“Firefighters from Bispham, alongside two fire crews from Blackpool and an aerial ladder platform from Morecambe attended the fire.
“Firefighters found that the fire was right through the property from the ground floor to the roof of a building.”