However, no one was injured in the incident, they said.
A call of fire at the ground floor (auction hall) of the building (Vikas Sadan) was received at 12.11 am. Fire tenders were rushed to the spot immediately and the fire was brought under control by 12.55 am, a Delhi Fire Services officer said.
The cause of the fire would be ascertained after investigation, but a short circuit is suspected, police said.
A DDA official said smoke due to fire was sighted around 11 am after which many employees ran out of the building while efforts were also made to control the fire before the firefighters arrived.
"However, no documents or important papers were destroyed in the fire," he added.