BERLIN — Most people who arrive by plane in Germany’s capital land at Berlin Tegel Airport, an austere, hexagonal airport beloved by locals for its no-frills aesthetic and efficient design.

But after decades shuttling air travelers in and out of the city, including more than 22 million in 2018, the airport, once an integral part of the Berlin Airlift, is preparing for its next chapter.

Shortly after the new Berlin Brandenburg International Airport opens in the fall of 2020, Tegel will shut down. The nearly two-square-mile airport will become Berlin TXL, a complex that will include much-needed homes, a vast research and industrial campus and a landscaped park, less than five miles from the leafy, canal-lined city center.

“In Berlin, our biggest problem is lack of space for new offices or residences,” said Kai Mende , a managing director for CBRE in Berlin. Office vacancy in Berlin was 2.2 percent in the fourth quarter of 2018, the lowest of any major German city. “In principle, the new Tegel project makes a lot of sense for Berlin,” he said.