Homeowners Michael and Julie Miller were shocked to discover a car had ploughed through a wall in their house during the early hours.
The couple thought there had been gas explosion when an enormous bang shook their house at around 0430 BST on Wednesday.
Julie Miller said the couple climbed through their bedroom window fearing a gas leak, until they discovered a car had come through the end wall of their home.
It is likely part of the house in Resolven, Neath, will have to be demolished before the occupants can return home.
Council structural engineers are assessing the property after the incident.