At approximately 3.21am this morning, CFS crews were alerted to a structure fire on Belair avenue, Port Willunga.

Five CFS trucks from Aldinga, Sellicks and Willunga arrived on scene to find the house fully alight.

Crews were able to contain the fire and stop the spread to neighbouring houses.

Fortunately the occupant home at the time evacuated uninjured, however was being treated by SA Ambulance for smoke inhalation.

Damages are estimated at $100,000 with Fire Cause Investigators to attend the scene later this morning.