The plane is believed to have flown out of North Perry Airport in Pembroke Pines but officials have yet to confirm the origin.
A witness said he saw the banner get snagged on something before it went down.
Roads in the area have been shut down as police and fire rescue respond to the scene.
7SkyForce HD flew over the scene where the wings of the plane could be seen separated from the aircraft and a tarp next to it, presumably covering the body of the pilot.
The aircraft is said to be from the company Aerial Banners Inc., which typically has their planes flying over Fort Lauderdale Beach and South Beach advertising festivals and events taking place across South Florida.
Fort Lauderdale Fire Rescue Chief Steven Gollan said the building was under construction but was occupied at the time of the crash.
He confirmed that the structural damage seen as a large hole on the side of the building was from the plane crash and not from the renovations.
There are no reports of injuries on the ground.