The Forest Towers of Milan and the Future of Sustainable Building

The author of recycled architecture makes the good point that these "green" buildings will require a lot of concrete, which is not a very sustainable building material. Relative to wood, it requires a lot of energy to produce and build with.


It turns out that the industry's already on it. According to this Time article, new concretes are being developed that not only require less energy in production, but also confer other environmental benefits. One example they cite is the titanium-dioxide containing concrete for the Jubilee Church in Rome, which filters pollutants from the air.

So as long as the energy input needed to manufacture concrete continues to fall and the architectural benefits, such as insulation, continue to improve, concrete buildings will approach an energy profile similar to that of wooden ones.


How long will it take? To give you an idea, Lafarge, one of the world's largest cement makers, has already reduced its carbon emissions per ton of production by 20% from its 1990 level. That's translated into a ten percent absolute reduction and was partly achieved by advances in making concrete stronger - ten times stronger - requiring less for a given building.

But that rate's bound to slow down and even once we have this wonder-concrete on hand, it'll likely cost more than aluminum or steel. Today's high performance concretes already are.


Given today's technologies, wood still looks like the most sustainable option. At least one prominent urban planning expert and the author of Cradle to Cradle, William McDonough, advocates employing wood as a primary building material for cities.