Three crews from Worthing and one from Shoreham were sent to the scene.
Steve Buchanan-Lee, GM operational training and development for the West Sussex fire service, took to Twitter to praise the firefighters' 'great life-saving work'.
He said crews had 'key support' from the South East Coast Ambulance Service and Sussex Police.
He wrote: "One male rescued from severe fire on first floor [and] all other persons accounted for.
"Full investigation now underway."