Four fire engines and around 25 firefighters tackled a fire at a construction site behind a commercial building on Chalk Farm Road in Camden.
Around one tonne of building waste was destroyed by the fire.
Control Officers took the first of seven calls at 1232 and mobilised crews from Kentish Town, Holloway and Euston fire stations to the scene. The incident was over for firefighters at 1351.
The cause of the fire is accidental and due to hot works.