Four fire engines and around 25 firefighters tackled a house fire on High Road in Ickenham.
Half of the ground floor was damaged by the fire and the roof of the bungalow was completely destroyed by the blaze. There were no injuries reported.
The house had no working smoke alarms.
A London Fire Brigade spokesperson said:: “This incident is a timely reminder about the importance of having smoke alarms in your home. Not having working smoke alarms leaves you and your loved ones at risk.
“Homes need multiple smoke alarms or you won't be properly covered. As a minimum, you should have smoke alarms on every floor of your home - in the hallways and the rooms you use the most plus a heat alarm in the bathroom and kitchen.
The Brigade was called at 0948 and the the fire was under control at 1057. Fire crews from Hillingdon, Ruislip, Harrow and Northolt fire stations attended the scene.
The cause of the fire is reported as undetermined.
A London Fire Brigade spokesperson said: “Firefighters recommend that you have a look at our online Home Fire Safety Checker to make sure there are no hidden hazards in your home.
“The online tool will ask you a series of questions that will help us work out the level of risk in your home, or the home of someone you care for. It only takes a few minutes to get tailored advice to keep yourself and loved ones safe from fire.”