A spoksman for West Sussex Fire and Rescue Service said crews were called to Mill Pond Way just after 11am to reports of a property on fire.
Three engines from East Preston, Littlehampton and Worthing all arrived to find a fire in the first floor of the house.
Crews wearing breathing apparatus quickly got to work on extinguishing the fire with two high pressure hoses and a covering jet, as well as a hydrant.
All residents have been accounted for, the spokesman said, and the fire has been extinguished. Firefighters are still at the scene damping down.
The spokesman added: “We would urge members of the public to avoid the area for the time being, and residents living nearby should keep their doors and windows closed.”
1. Mill Pond Way, East Preston
Fire crews on the scene SUS-210128-130254001 Photo: SUSSEX NEWS AND PICTURES
2. Mill Pond Way, East Preston
Fire crews on the scene SUS-210128-130305001 Photo: SUSSEX NEWS AND PICTURES
3. Mill Pond Way, East Preston
Fire crews on the scene SUS-210128-130126001 Photo: SUSSEX NEWS AND PICTURES
4. Mill Pond Way, East Preston
Fire crews on the scene SUS-210128-130137001 Photo: SUSSEX NEWS AND PICTURES