The walls do not conform with fire safety regulations, Karsten Mühlenfeld, director of BER airport, told a meeting of the Brandenburg parliament, Tagesspiegel reports.
"We have found a large number of walls which are defined as fire safety walls, but have not been built in such a way," the airport boss confirmed.
Mühlenfeld said that the discovery was made after airport authorities set a provisional opening date for the building for the second half of 2017, indicating that Berliners will have to keep waiting for the first flights to leave their new airport.
The airport was originally slated to open in 2012, but has been hit by numerous problems with fire safety conformity as well as the bankruptcy of the company supposed to supply internal equipment.
Monday's revelation led a group of Christian Democratic Union (CDU) politicians, led by Jens Koeppen, to call for the complete demolition of the building.
But Mühlenfeld described such a notion as "nonsense", arguing that for the most part, the walls would not need to be completely rebuilt.
Stefan Evers, CDU leader in Brandenburg, said that "calls for a demolition are populist nonsense. But with 600 walls being torn down, we're coming pretty close to a demolition anyway."
There was some good news, though, as Mühlenfeld told the parliament that builders could return to the building as early as next week after they were ordered to down tools earlier in the month due to fears over the safety of the terminal roof.
Officials said workers were not allowed into the main hall of the terminal until an inspection had taken place on ventilator systems which were too heavy for the structure to hold.
Structural analysts found that the weight supported by the roof had massively exceeded the original load the building was supposed to bear.
Mühlenfeld said that the struts supporting the ventilators would be provisionally reinforced before a more permanent solution was found.