The wall void from the ground to the fifth floor of a five-storey house is alight.
Station Commander Jon Singleton, who is at the scene, said: “Firefighters are tackling a complex fire at a town house.
“Crews are using specialist cutting equipment to gain access to the fire and are working swiftly to bring it under control. A turntable ladder is being used to provide a bird’s eye view and monitor the incident.
“Roads in the local area are closed whilst firefighters work to make the scene safe, so we encourage local people to avoid the area.”
The Brigade was called at 1254. Fire crews from Kensington, Hammersmith, North Kensington and Paddington fire stations are at the scene.
The cause of the fire is not known at this stage.