Feature: Daring new innovative structures claim to turn Rotterdam greener

With innovative and emblematic constructions, Rotterdam pledges to enrich its imposing skyline and step closer to becoming the most sustainable harbor in the world.

At the heart of this effort, is the Windwheel, a high-tech version of the Dutch traditional windmill whose circular design was unveiled last week.

The Windwheel "will be comprised of two mega-rings, two separate buildings, which only touch at the top," said its South African architect Duzan Doepel, unveiling the design during a presentation in Rotterdam.

The inner ring will house offices, 72 apartments, shops and a seven-floor hotel. The outer ring will feature a "wheel" made of 40 large cabins, running a 30-minute "ride" and offering visitors panoramic views of Rotterdam and neighboring areas as far as Delft or Kinderdijk, the Dutch site featuring the largest concentration of old windmills in Europe.

Each cabin will be equipped with smart walls displaying digital layers of data. Holograms in the cabins serve as a virtual tour guide.

The designers also aim at creating an innovative platform of clean technology and sustainability. Offering energy positive output, the 174-meter-tall building fits in Rotterdam's plans to cut its carbon footprint by 50 percent by 2025 and to have all new buildings energy neutral by 2020.

Because its foundation will be underwater, the Windwheel will look as if it is floating on the river Maas, but its final location is still under discussion.

The spectacular project, scheduled to be completed in 2025, is estimated to attract 1.5 million visitors a year. Endit