Architect and sustainable design expert William McDonough exhorts green building designers not to be content with just “doing less­-bad” de­signs that put off the day of reckoning for excessive energy and water use, but to design buildings and cities that are “positively good.” When our focus is primarily on “eco-­efficiency,” that is, reducing our negative im­pacts, we are not likely to achieve design breakthroughs. For example, sav­ing 20% of the energy of a standard building is a virtue, but energy use still creates lots of carbon dioxide emissions and pollution from electric power production. If we save 30% of the water use of a standard building, we are still using far more water than the building receives as rainfall.

Some experts tell us that our environmental impacts have to be re­duced 90% or more to begin to reverse the decline in the Earth’s support­ive ecosystems and to relieve the stress on energy and water resources. Such a “Factor 10” building is a long way from our current focus on “Factor 1.5” buildings that might reduce impacts of building construction and op­erations by 33% on average. (At this time, a good LEED­ certified building reduces water use by about 30% and energy use by 30% to 50%, compared with the average of all buildings).

Economists have long analyzed the “externalities” of modern life, wherein a factory, for example, is more profitable when it is able to unload its pollution and resource depletion on the environment, without having to pay for all the consequences. One can think of the past 30 years of pollu­tion control regulations as an attempt to make business and government “internalize” the full external costs of their pollution, so that they would decide not to create it in the first place. 

In an “eco­-effective” analysis, one would “internalize the externalities,” for example, by performing a life­cycle analysis of all materials produced, including their upstream (cost of materials, cost of transportation, type of labor) and downstream (recyclability, reusability) environmental and so­cial costs. Sustainability implies that, together, we have to agree to live prima­rily on “natural capital” (renewable resources and biodiversity) for a long period of time, using non­renewable resources at a much slower rate, per­haps eventually not at all.