Four fire engines and around 25 firefighters tackled a fire in a garden on Everglade Strand in Colindale.
A garden behind a row of houses was destroyed, along with part of the ground floor of one property. There were no reports of any injuries.
The fire is believed to have been accidental and caused by a bonfire 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 check your local authority’s advice on bonfires and follow our safety tips on our website.”
The Brigade's Control Officers took the first of 20 calls to the fire at 1916 and sent crews from Hendon, Stanmore and Finchley fire stations to the scene. The fire was under control by 2013.