Four fire engines were sent to the scene in Lock Lane at around 10:55 this morning.
Crews wearing breathing apparatus extinguished a blaze in the property's living room.
There are no reported injuries, and people are being advised to avoid the area and keep their doors and windows closed if they live nearby.
A spokesperson for West Sussex Fire & Rescue Service said: "We were called at 10:55am to a house fire in Lock Lane, Birdham.
“Joint Fire Control mobilised four fire engines to the scene.
“Firefighters wearing breathing apparatus worked quickly to extinguish a fire in the living room.
“Three crews currently remain at the scene damping down and ensuring there are no further hot spots.
“People are being advised to avoid the area and keep their doors and windows closed if they live nearby.”
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