The deceased, identified as Rinku, was the owner of the four-storey building in which the fire broke out and was a scrap dealer.
The residential building had a scrap-storage facility from which the fire is suspected to have originated, said a police official.
The fire was reported around 8.30 AM and three fire tenders were rushed to the spot. Teams of police and Delhi Disaster Managament Authority followed, said a senior government official.
A rescue operation was launched and Rinku was rushed to a hospital where he was declared brought dead, said police.
A case under relevant sections of law has been registered against unknown persons and investigation is underway, police added.