Part 3 in the Series: ‘Solving the Problem with Roofs’

Green roofing seems like an obvious step in solving the problem with roofs.

Urban environments often have limited green space, and using our rooftops in this manner has many advantages, including the provision of habitats for nature that otherwise may not exist.

Both the California Academy of Sciences and the Vancouver Convention Centre have large green roofs, planted with thousands of indigenous plants, and through monitoring species that visit the site, both have seen a significant increase in the variety and quantity of wildlife visitors.

A rooftop garden also has financial benefits, as a dense green roof is as a highly efficient form of insulation. The United States Postal Service has a 2.5 acre green roof on their New York building, which saves them $30,000 every year on heating and cooling bills.

There are social benefits too, as green roofs can play the role of a public park in an urban environment without natural space.

In the countryside however, a green roof has less purpose. Habitats for wildlife already exist, and there is much more access to natural space in rural populations. And even though a rooftop garden absorbs carbon, it doesn’t become carbon negative immediately, taking about seven years to counteract the carbon emissions involved in its construction.

However, the potential for combining nature and architecture is much more significant than just green roofing. Dr Rachel Armstrong believes in a future where buildings become living things. Central to her philosophy are protocells – small fat cells that absorb carbon dioxide and solidify it. Essentially, they turn into rock, filling cracks in buildings, and according to Armstrong, could even be used to prop up Venice and stop it from sinking.

She also sees slime mould as a key player in sustainable urban living. It can be grown to remove impurities from the air and sewage, and could potentially be used to solve planning issues:

Owing to their effective internal organisation, slime mould can solve simple mazes to find the shortest path to food. Slime mould organisms could physically ‘solve’ population mapping in urban landscapes by calculating a number of pathways and respond with a physical map based on biological decisions.

Even though it may be hard to see urban planning evolve in the way she predicts, it is clear that the convergence of nature and architecture has many benefits, and is a key step in solving the problem with roofs.

Image courtesy of De Boer Hello on flickr