Firefighters evacuated a number of residents in Montgomery Street in Maidstone after a suspicious blaze broke out on Monday night.
A number of callers to triple-zero around 10.20-pm said flames were visible in the living room at the front of an unoccupied unit.
MFB crews arrived to find a single-storey unit well ablaze.
Firefighters entered the burning unit to search for squatters or other occupants but nobody was found inside.
More than 20 firefighters fought to protect surrounding homes from radiant heat, evacuating eight residents from a neighbouring property.
A community warning was issued for smoke in the area and the fire was declared under control in 16 minutes.
The exact cause of the blaze is yet to be determined and police are treating it as suspicious.
An arson chemist is attending the scene on Tuesday morning.