When it comes to building a bridge, what prevents it from having the most enduring and sustainable life span? What is its worst enemy? The answer is, simply, the bridge itself—its own weight.

Built with today’s construction processes, bridges and buildings are so overly massed with energy and material that they’re inherently unsustainable.

While concrete is quite literally one of the foundations of modern construction, it’s not the best building material. It’s sensitive to pollution. It cracks, stainsand collapses in reaction to rain and carbon dioxide. It’s a dead weight: Take San Francisco’s sinking, leaning Millennium Tower as an example.

Reprinted courtesy of Massimiliano Moruzzi, Construction Executive, a publication of Associated Builders and Contractors. All rights reserved.