A rendering of SKYPARK, a hotel being added on top of an existing shopping center, in Berlin.

With property in high demand in Berlin—it had the largest year-over-year real estate price increase of any city in the world last year—it makes more sense than ever to look up for new opportunities. A number of developers have found success (or are hoping for a top return) from add-on projects atop existing structures in Germany’s capital.

The idea of building up came up multiple times in a discussion of flex space and mixed-use buildings at ULI Germany’s Urban Leader Summit in Frankfurt in May. Developers in Germany are excited about the concept of flex space but believe it requires much planning and forethought. Completed or in-progress projects that take mixed-use concepts to new heights could be trailblazers.

In the mid-1990s, shopping malls were an easy sell in the newly capitalist East Germany, and ECE Projektmanagement built a number of them along Berlin’s commuter train lines. At Frankfurter Allee, the first part of the Ring Center was completed in 1995, and additions built in 1997 and 2007 brought the total retail space to more than 45,000 square meters (480,000 sq ft). The great accessibility to public transit means the parking garages are emptier than ever. Hotel developer MQ Real Estate had an idea: Why not turn the mostly unused top deck into a site for a new modular hotel?

The first-of-its-kind hotel, called SKYPARK, will be constructed from prefabricated pods within a few weeks this fall on the roof of the parking garage. The wooden prefab pods were sustainably produced in Germany and will be arranged on the deck to create a one-story hotel. The €10 million (US$11.7 million) project consisting of 151 rooms over 8,000 square meters (86,100 sq ft) is incredibly cheap by hospitality standards. ECE and Deutsche Asset Management are also partners on the SKYPARK project, which will fall under the niu brand of NOVUM Hospitality.

SKYPARK is not the first unusual use of a parking deck roof in Berlin. Klunkerkranich, a combination concert venue, community garden, and café, has been a favorite hangout in Berlin’s gritty Neukölln district since 2013. You can’t see it from the street—it’s on the top deck of the Neukölln Arkaden parking garage, which is also owned by ECE. It takes up about 2,500 square meters (26,900 sq ft) full of community-built garden boxes and wooden decks, a true urban oasis. On the other side of town, Deck5 has been operating as a sand-strewn beach bar on the top deck of the Schönhauser Arcaden parking garage.

In recent years, Berlin has become more open to mixed-use developments where supermarkets on the ground level are topped with apartments. To keep up with the demands of its ever-growing population, Germany’s capital city will need to build nearly 200,000 apartments by 2030. Neighborhood supermarkets such as REWE, Aldi, and Lidl classically build a single-story structure with a parking lot. But the new idea is to fit stores on the ground floor of existing apartment buildings or tear down old supermarkets to build up and offer more density. These are neighborhood stores, so developers believe the lack of parking won’t be a problem.