[22] The construction permit was granted only under the condition that once operational, the number of people living in the approach path would be lower compared to the situation surrounding the three existing airports – Tegel, Schönefeld and Tempelhof.

The key directive of the verdict was that rooms must be provided with adequate ventilation if windows are closed for noise, and the airport authority must also determine how air inside the structures can be vented.

[50] Although the airport had yet to open, officials were already planning a possible third runway for approximately €1 billion, and other new projects, such as an additional terminal, expanded baggage system and another freight facility.

[66] At the end of August 2018, Berlin's head of finance, Matthias Kollatz, remarked that the airport may face abrupt bankruptcy on 1 January 2019 if no immediate measures were to be taken.

When the planned opening date of 2 June 2012 drew nearer the FBB launched a marketing campaign introducing the BER branding, reflecting the new airport code.

[122] The Institute for Federal Real Estate has been planning to construct a terminal on the northern edge of the airport for use by government officials and to welcome foreign dignitaries during state visits.

As a member of the Oneworld airline alliance, Air Berlin required airport facilities capable of meeting the demands of its connecting passengers that Tegel could not provide.

However, Air Berlin filed for insolvency on 15 August 2017 and large parts of it were bought by Lufthansa, Germany's largest airline, ahead of its collapse on the 27th of that month.

In 2021, the airport authority sought to establish 25 long-haul routes from Berlin by 2025 including negotiations for a revised bilateral agreement to allow Emirates to serve a fifth German city.

Deutsche Bahn confirmed in August 2011 that multiple daily Intercity-Express and InterCity trains will connect the airport to Bielefeld, Hannover, Hamburg, Dresden and Wolfsburg.

The issue is complicated by the fact that the line would have to cross the state border between Berlin and Brandenburg and it is unclear who would have to pay for which parts of construction operations and maintenance.

[1] Schönefeld's refurbished passenger facilities were incorporated as Terminal 5 on 25 October 2020[9][10][11] while all other airlines completed the transition from Tegel to Berlin Brandenburg Airport by 8 November 2020.

FBB proposed an interim solution employing up to 700 human fire spotters, which the building supervision department of the local Dahme-Spreewald district rejected.

[339] Another major factor impacting on the construction of the airport was insolvency of general planner Planungsgemeinschaft Flughafen Berlin Brandenburg International (pg bbi) and the dismissal of the Gerkan, Marg and Partners architects.

[371] Citing dissatisfaction with construction progress, members of the airport board indicated during their 8 December 2014 meeting that they were beginning the search for a new CEO, although Mehdorn's contract ran through 2016.

In fact, the Federal Railway Authority demanded that the commuter trains be simulated at speeds up to 100 kilometres per hour (62 mph) when entering or leaving the station.

[413][414] To prevent suffocation in an emergency, glass towers are to be built inside the railway station that connect to openings in the roof, which will provide fresh air.

Interested citizens forced a non-binding public quorum that was held parallel to the federal election, asking whether Tegel should remain open if BER was already in operation.

[465] In November 2017, an audit of the entire airport by Germany's technical supervision service TÜV uncovered more significant lapses in the fire and emergency systems, further pushing back estimates.

[473] More people than previously expected would be moving through the main terminal, causing an increase in fire emergency load, with even more passengers arriving through the railway station in the basement.

"[475][476] Personnel changes continued to affect the project, with the head of the technical department Jörg Marks leaving the company on 19 April 2018, and Brandenburg's state secretary for airport affairs Rainer Bretschneider going into retirement in June.

[483] In June Berlin's assembly formed a new committee of inquiry to uncover responsibility for ongoing construction lapses and to investigate possible sources of further delay.

[491] In May 2019, it was reported that sand-lime brick used in the foundations of the airport were not sufficiently rated for load, necessitating a costly replacement of much of the underground cabling and reinforced concrete beams.

[497] German minister of traffic Mr Scheuer however reiterated his concerns that the sand lime brick and cable duct issues could delay the opening beyond 2020.

[507] In late July 2019, Lütke-Daldrup stated that, of the more than 11,000 shortcomings reported in March 2019, over 70% had been resolved, including several hundred problems of high priority that would preclude the start of the final TÜV rehearsal.

The concrete foundation needed to be partly rebuilt to accommodate technical systems,[510][511] with issues in the wiring arrangement and the ability to withstand sustained usage and heat.

[516] By mid-February, the planned opening continued to be doubted upon because 5,000 issues still required rectification and certification by an external inspection company (TÜV) in order to complete construction by the end of the first quarter of 2020.

[533] On 15 October 2020, all test runs of the airport's passenger facilities and procedures, which included thousands of volunteers since spring, concluded successfully after being slightly delayed by the COVID-19 pandemic.

[537] In September 2010, Deutsche Flugsicherung published aircraft arrival and departure routes for Berlin Brandenburg Airport which significantly differ from earlier ones used in the court decision for the construction permit.

Therefore, aircraft would now fly over areas in southern Berlin (Lichtenrade, Steglitz and Zehlendorf) and adjacent Brandenburg (Teltow, Stahnsdorf, Kleinmachnow and Potsdam) to the surprise of local residents.