Four fire engines and around 25 firefighters tackled a fire on Wood End Gardens in Northolt.
A range of sheds and outbuildings to the rear of the property were destroyed by the fire. Half of the roof of a single storey annex was damaged by the fire. There were no reports of any injuries.
The fire is believed to have been caused by unattended burning spreading out of control.
A London Fire Brigade spokesperson said: "We would urge people to consider if their bonfire is necessary and to take care if you’re burning waste at home or at work.
"If you’re having a bonfire never leave it unattended and consider your neighbours if you do decide to have a fire in your garden.
"Make sure you build it clear of buildings, garden sheds, fences and hedges and never use flammable liquids to start it or burn dangerous items such as aerosol cans. Always keep a bucket of water or a hosepipe nearby in case of fire.
“Always check your local authority’s advice on bonfires and follow our safety tips."
Control Officers took the first of 32 calls at 1207 and mobilised crews from Wembley, Harrow and Southall fire stations to the scene. The incident was over for firefighters at 1310.