Arsonists destroyed a flat bed tipper truck parked on the driveway of a house in Accrington.
Firefighters from Hyndburn Fire Station were called to Wordsworth Road at 3am yesterday.
Fire services say the blaze was started deliberately and the heat from the flames caused a window of the house to crack.
Crew manager Darrell Sturgess said: "The Ford Transit tipper truck was full at the time of the arson and the fire caused the hydraulics to play up.
"It was lifting itself up and down without anybody operating it and we thought that it might empty itself but it didn't."
Police said the incident is being treated as arson and an investigation is under way.