Ford’s $18 Million Roof

The year was 1917, and Ford Motor Company was flying high. Its groundbreaking Model T was in the ninth year of production, delivering affordable travel to the middle class worldwide. It was time to build a new plant. Eleven years later, the completed Ford River Rouge Complex in Dearborn, Michigan, had become the largest integrated factory in the world.

Nearly a century after, William McDonough signed an agreement with Ford Motor Company to redesign this famous 1,212-acre(490 hectare) Rouge River facility. Among many details of the 1999 proposal, one caused the most hesitation. McDonough proposed to cover the roof of the 1.1-million-square-foot (100,000 square meters) Dearborn truck assembly plant with nothing other than… moss. Well, some trees were involved, too.

Met with resistance and dismissal for being such an unusual decoration, the roof was anything but. McDonough explains:

After lots of discussion and several visits to buildings with green roofs, [Ford’s] Jay Richardson’s skepticism began to give way. The US Environmental Protection Agency was developing new storm water regulations, and Ford had estimated that the conventional technical controls required to comply with the new rules could cost almost $50 million. The natural storm water management system was estimated to cost only $15 million. The math was simple and compelling: the living roof offered millions of dollars in savings, with the landscape thrown in for free. Kind of gets your attention.

The result? With a final price tag of $18 million, the installed lightweight roof delivered savings of approximately $30 million, compared with the cost of conventional storm water management systems. Over one million square feet of roof got covered with sedum—a low-growing plant—enough to clean up to 20 billion gallons (or about 75 billion liters) of rainwater annually with zero energy, compared with a heavy system requiring its own power supply. Improved biodiversity and landscape in a heavily degraded industrial environment was a welcome bonus, and the roof became a disruptive idea demonstrating the line-to-circle principle at work: feeding a healthy nutrient (clean water) back to the soil in the most natural way possible, while at the same time preventing flooding by playing a retention role. No wonder the New York Times called it an economic necessity, echoing the words of Bill Ford, then Ford’s chief, spoken at the completion of the roof in 2002: “This is not environmental philanthropy. It is sound business.”