Although more of us than ever are choosing to live in cities, that doesn't mean we have lost our love for green open spaces. The popularity of parks and areas which haven't been wholly taken over by urban development suggests we haven't lost our yearning for something other than man-made materials. Caroline Brahme's Grey to Green is a concept designed to add a splash of natural color back to urban areas.

Grey to Green is a very simple idea that, once seen, makes you wonder how no one has thought of it before. It's essentially paving slabs with holes built into them. These holes can be filled with soil, allowing plants or grasses to grow through them. Nature already tries to repossess roads and pavements by pushing greenery through or even creating cracks in surfaces – Grey to Green calls a truce with Mother Nature, giving it space to co-exist with us even in the harshest of environments.

Brahme has included several different designs in her concept, with differing numbers of holes allowing different amounts of vegetation to take hold. This caters for easy customization, with city planners able to integrate Grey to Green into any existing paved surface. This has the potential to turn an urban wasteland into, if not a green and pleasant land, at least a more beautified environment.

Each Grey to Green paving slab costs around 90 SEK (US$14), though the final price depends on which particular design is chosen.

View gallery - 5 images