Police are appealing for information to a wilful fireraising which caused substantial damage to the historic Coach House on Boddam’s Rocksley Road.
Emergency services were alerted to the blaze just before 6am on Wednesday.
Firefighters from Peterhead and Ellon worked through the morning to bring the blaze at the unoccupied house under control.
Incident Commander, Station Manager Mike Cordiner, said: “Our crews arrived to find the single-storey building was well-alight and immediately began firefighting operations. The roof had suffered a partial collapse before firefighters arrived and the structure was highly unstable, but thanks to the close partnership with our police colleagues we were able to confirm all people were accounted for.
“Both wholetime and retained personnel tackled this fire, and all the firefighters involved worked closely to make best use of the water supplies and bring the fire under control as quickly and safely as possible.
“This incident shows the vital role of retained firefighters within their communities and demonstrates the great working relationship between our wholetime and retained crews.”
The building sustained significant damage as a result of the fire and specialist officers from the SFRS Fire Investigation Unit in Aberdeen will conduct a joint investigation with Police Scotland.
Officers are appealing to anybody who may have been in the area at the time of the fire to get in touch with them.
Anyone with information is asked to contact Police Scotland on 101 or Crimestoppers on 0800 555 111 if they wish to remain anonymous.