With the world population slated to reach 9 billion people, housing becomes a real problem. But Japanese construction firm Shimizu Corp has an innovative idea to solve this. Ocean Spiral is planned as an eco-friendly underwater city that would house 5,000 people and be powered by the sea bed.

An artist’s rendering shows the futuristic structure divided into three sections. A floating sphere – the “Blue Garden” – will be 500 meters (approx. 1,640 feet) in diameter. It will lie just beneath the ocean’s surface but its top will just breach the surface. It will feature 75 floors of space designed for business, residential, commercial and research areas.

Below this will be a 15 kilometers long spiral path that winds 3 to 4 kilometers down to the ocean floor.Scientists will use this space to discover ways to excavate energy resources from the seabed. The spiral will end at the “Earth Factory”, which will be anchored on the sea bed. Connected to similar satellite facilities via transport tunnels, these “factories” will store, treat and reuse CO2, along with cultivating and developing deep sea resources.

A highly ambitious undertaking, all this will be built on the surface of the ocean. The company believes the project will cost around ¥3 trillion ($25.5US billion) and could be completed within 15 years.Sounds like sci-f\i but stay tuned. With enough money and ingenuity, it just might become reality.