One fire engine and a technical rescue unit were sent to the house in Poplar Close, Crawley, at 12.30pm and on arrival reported that the house was ‘severely damaged’.
A West Sussex Fire and Rescue Service spokesman confirmed a family-of-five were inside the house when the tree fell but there had been no reports of any injuries.
She said: “There are no reported injuries but a family of five have had to leave their home.
“The property next door has been evacuated as a precaution whilst we await the attendance of CBC Building Control Officer.
“The Red Cross has also been requested to help.”
Sussex Police confirmed a tree surgeon arrived at the scene around 1.45pm, and made the area ‘as safe as possible’ before handing it over to the occupants.
Fire crews and the tree surgeon left the scene at around 6.20pm.