Forget about rooftop gardens, rooftop campsites and rooftop farms, we need our roofs to solve a much bigger problem — to store bikes. The engineers at IBA, the Amsterdam Department of Engineering, came up with the idea to install Velominck bike storage facilities on top of the city’s roofs.

Why? Because Amsterdam has a pretty huge bike storage problem. With almost 300,000 bikes in public space and only 200,000 official parking spots, some 100,000 bikes are parked ‘illegally’. There have been lots of experiments with underground bicycle parking garages, floating platforms and even our infamous bike parking flat (a big tourist attraction), but there’s still a lot of space left on the urban rooftops. With a public transport chip card, the Dutch variant to the Oyster Card, one should be able to store a bicycle. An elevator transports the bike to the roof where it will be stored automatically until the owner comes back and checks out with the card. According to its makers, the first rooftop parking system should be completed within five years. I guess it will be another attraction for tourists that can see the bikes go up and down in the transparent elevator.