In the southern Belgian province of Namur, concrete and bricks from demolished buildings are being turned into eco-friendly road surfaces.

Each year, the European Union produces three billion tonnes of waste. This equates to six tonnes of solid waste for every EU citizen, according to Eurostat. A major challenge is findings ways to reduce and reuse a large amount of such waste .

Twenty five years ago, the German chemist Michael Braungart developed a new approach to recycling, now called "Cradle to Cradle" or "C2C" after the book, Cradle to Cradle: Remaking the Way We Make Things, which he and the American architect William McDonough published in 2002.

Every day cities in Europe discard a useful nutrient-rich resource that could be used to grow crops. Ironically, we treat and process human wastes while we mine non-renewable phosphate and potassium and we consume fossil fuel to make nitrogen fertiliser.

Vehicles seats are normally made of polyurethane foam, a thick material that is expensive to recycle and ends up in dumping sites or being incinerated.

Non-ferrous metals are increasingly in demand because of the electronics industry. "They are used in LED’s, computers, smartphones; this is a much bigger business now," says Kate Hornsby , Waste in Social Environment manager at the Technical University Aachen , Germany.