It is a work of art created by sculptor Hedva Ser, who is a UNESCO Goodwill Ambassador, the organisation says
The fire service said smoke was spotted at the fifth floor of the seven-storey building around 10:30am.
Three units from the Kurmitola Fire Station put out the flames soon after reaching the spot.
"We suspect it started from a spark erupting from a portable generator and engulfed the wastes papers piled nearby," said the fire station's Senior Officer Niaz Ahmed.
The forest department's Wildlife Conservation Inspector Abdullah Al Sadik told bdnews24.com that smoke started billowing out of the generator room on the fourth floor around 10:30am.