Six fire engines and around 40 firefighters tackled a fire at a detached house on Plaistow Lane in Bromley.
The first floor was destroyed and half of the ground floor was damaged by the fire. There were no reports of any injuries.
One of the Brigade's 32-metre turntable ladders was used at the scene as a water tower to help fight the fire from above.
Control Officers took the first of 12 calls at 0404 and mobilised firefighters from Bromley, Beckenham, Lee Green and surrounding fire stations attended the scene. The fire was under control by 0651.
The cause of the fire is under investigation.