A man has offered a £10,000 reward to help catch arsonists who destroyed a North Yorkshire house he was restoring.
Dale Head House in Ryedale was 10 months into an extensive programme of renovation when it caught fire overnight between 23 and 24 May.
Jonathan Reed has owned the derelict house for two-and-a-half years and intended to live in it once the renovation work was finished.
He has urged anyone with information about the arson to contact police.
A builder who was staying at the site woke to find the property on fire.
Det Sgt Ian Fieldsend, of North Yorkshire Police, said: "This incident has cost the victim an awful lot of money and has more or less destroyed a project which he had spent a lot of time and effort on.
"We are appealing to anyone who travelled along the Hawnby to Osmotherley road between 2100 BST on Sunday 23 May and 0400 BST on Monday 24 May to get in touch with the police if they saw any suspicious people or vehicles."
Mr Reed said: "My intention was to live in the house part-time and as an architect brought up in the area with strong local connections, I intended to retire to the house.
"The incident is upsetting because so much time and energy has been invested over the past year by many talented local crafts people.
"All the materials were sourced locally and as the house is in such a sensitive location we were hoping the result would be a landmark renovation within the National Park.
"It looks like a mindless act of vandalism has prevented this from ever happening. It has destroyed a fantastic house in a beautiful area and has probably cost me £500,000."