Firefighters from Keighley and Bingley tackled a blaze in the attic of a house in Stockbridge.
Crews were called to the house in Bradford Road at around 6pm on Tuesday after the householders came home and heard the smoke alarm sounding.
A spokesman for Keighley Fire Station said the fire, believed to be caused by an electrical fault, had been smouldering through the afternoon.
He added: “They were quite lucky, they’d been out for the majority of the day while the fire had been been developing. They did the right thing by getting out of the house and calling us."