Eight fire engines and around 60 firefighters tackled a house fire on Vernon Drive in Harefield.
Half of the ground floor and half of the roof of a detached house were damaged by fire. The whole of the first floor was destroyed. There were no reports of any injuries.
Firefighters removed and cooled three gas cylinders to an ambient temperature as a precaution as some cylinders can explode when exposed to heat.
The Brigade's 999 Control Officers took 18 calls to the blaze.
There were road closures in place and people were advised to avoid the area where possible.
The Brigade was called at 0854 and the fire was under control by 1150. Fire crews from Heathrow, Harrow, Hillingdon, Ruislip and surrounding fire stations attended the scene, alongside crews from Hertfordshire Fire and Rescue Service.
The cause of the fire is under investigation.