Reviving the skies: $8 billion initiative to transform Berlin's abandoned airport into a green metropolis | Dinogo

At Berlin's former Tegel Airport, workers continue to discover remnants of bombs. This 495-hectare site, once home to the city's main airport until its closure in 2020, holds traces of the Prussian military and the devastation of two world wars. Originally cleared for runways in the 1970s, many areas remained untouched. Since May 2021, more than 10 tons of explosives and munitions have been safely removed or detonated from 20 hectares of land.

The Berlin TXL project aims to create a climate-conscious community packed with cutting-edge sustainable technologies. Featuring an integrated university campus and innovation hubs, it’s envisioned as the future of urban living—one that hopes to inspire generations to come.

Backed by the State of Berlin and leveraging publicly owned land, the developer Tegel Projekt is teaming up with public and private sector partners to bring the Schumacher Quartier to life. This car-free neighborhood will house about 5,000 residents, while The Urban Tech Republic will offer space for 5,000 students and host up to 1,000 companies.

Nicolas Novotny, the design and development director at Tegel Projekt, shares with Dinogo that the vision for the project dates back to 2012. He highlights the challenges the world faces in the 21st century—resource scarcity, climate change, energy crises, and rapid urbanization—and explains that the project focuses on finding solutions across energy, mobility, water, recycling, materials, and communication.

Looking globally for inspiration, Novotny points to high-tech communities like Barcelona's 22@ district, Abu Dhabi's Masdar City, and Toronto's now-canceled Sidewalk project backed by Google. However, much of Tegel’s approach is homegrown, developed in collaboration with private companies.

The project is designed to be net-zero energy, meaning it will generate and consume all its power on-site. Novotny explains that photovoltaic panels and geothermal energy will be harnessed to produce electricity, while Tegel Projekt has partnered with energy company E.ON to implement an innovative heating and cooling system called LowEx.

The geothermal heat will work in tandem with heat sourced from industrial operations and the city’s sewer network, along with biogas, to power a 12-kilometer (7.4 miles) system of underground water pipes. These pipes connect to heat exchangers and pumps to warm buildings, and on hot days, the system can extract heat from buildings to cool them down, storing it within the network.

Inside the Schumacher Quartier

In the residential area, homes will be built using locally sourced wood, with roofs adorned with greenery. The project is collaborating with animal-design specialists from the Technical University of Munich and the University of Kassel to create habitats for local wildlife, including kestrels and Eurasian swifts.

The neighborhood will feature schools, daycare centers, shops, sports facilities, restaurants, and bars, transforming it into a vibrant hub, not just a housing complex. 'We don’t want it to be a dormitory city,' Novotny says.

Streets in the area will be car-free, promoting cycling, e-bikes, and scooters. For the elderly, however, alternative solutions are being explored, including delivery robots for tasks like grocery shopping.

As part of the 'sponge city' approach, rainwater will not enter the sewer system. Instead, it will be captured, reused, absorbed into the ground, or allowed to evaporate, providing natural cooling to the environment.

The Urban Tech Republic

The Urban Tech Republic, a vast innovation campus and industrial park, will span nearly four times the size of the residential area, with even bolder ambitions.

BHT University (Berlin University of Applied Sciences and Technology) will occupy the iconic hexagonal Terminal A of the former airport. Terminal B will be transformed into a startup hub featuring a conference center and showrooms, while Terminal D will house laboratories. The surrounding infrastructure will serve as a 'living lab street' to test new mobility technologies, according to Novotny.

The vision for the site includes providing students with space to continue developing their ideas after graduation, offering flexible rental spaces for startups.

There will be thoughtful references to the site’s history, Novotny explains. Since the terminals are protected, nearby streets and sidewalks will be constructed using recycled runway concrete, in compliance with building regulations. A competition is underway with companies to develop these recycled materials, he adds.

A Berlin 'gem'

Dr. Johanna Sonnenburg, an urban development consultant and associate at the Technical University of Berlin’s Center for Metropolitan Studies, points out that the project has been delayed for years due to the completion of Berlin Brandenburg Airport, which replaced Tegel.

Berlin TXL’s ideas are forward-thinking, she says, but 'they are not as groundbreaking as they were when initially conceived 10, 8, or even 5 years ago,' given how quickly the field of sustainable development is evolving.

Sonnenburg also mentions the challenge of integrating Berlin TXL into the city. 'Tegel isn’t very well connected,' she notes, pointing out that the former airport lacks a rail link, with the only underground connection being located at the Schumacher Quartier in the northeastern corner.

Despite these challenges, Sonnenburg describes the project as a 'gem' in Berlin’s infrastructure development, a standout in the city’s transformation.

The project's impact may reach far beyond Berlin. Concepts like constructing the Schumacher Quartier from wood could spark discussions on environmental, social, and governance (ESG) standards in the real estate sector. 'I really hope they succeed… it would be great for both Berlin and Germany,' says Sonnenburg.

1,000 abandoned airports

Berlin TXL is not the only repurposed airport project—Tempelhof Airport, once one of Berlin's busiest, became the city’s largest public park in 2010.

In Quito, Ecuador, the Old Mariscal Sucre International Airport, once considered one of the world’s most dangerous airports, was transformed into a park after its closure in 2013. Some other former airports, like Galeville Military Airfield in New York, which shut down in the 1990s, have been reclaimed by nature and are now part of the Shawangunk Grasslands National Wildlife Refuge.

The potential for repurposing old airports into vibrant communities is becoming increasingly evident. Brooks City Air Force Base in San Antonio, which closed in 2011, has since been converted into a 1,300-acre mixed-use development, offering residential, commercial, and educational spaces while preserving the original runway.

A bold proposal for the redevelopment of Downsview Airport in north Toronto was recently unveiled, with plans to build homes for over 80,000 people and 12 million square feet of office space. Like Berlin TXL, the project will incorporate sustainable technologies throughout its design.

With more than 1,000 abandoned airports across the United States, according to a 2019 research paper, there are countless more sites ripe for repurposing.

Work has already commenced at the site of the old Tegel Airport, with the goal of completing the project by the late 2030s.