According to Green Versus Sustainability: From Semantics to Enlightenment by Yanarella, Levine and Lancaster, ‘green’ refers to individual products and processes. Instead of addressing the overall system in a product’s (or building’s) life, ‘green’ describes single, separate aspects. Sustainable, on the other hand, relates to the whole system encompassed by design, manufacture, and purchase, from concept through disposal.
If something is sustainable it is meant to meet the needs, enhance the quality, and prolong the cycle of life, human or non. Sustainable decisions and actions are those that cause no harm and consider the long term effects.
So depending on the entire scope of a project’s conception and construction, a building with green parts isn't necessarily sustainable. Building sustainably takes more time and effort than a split second decision to specify materials with recycled or recyclable content. A truly sustainable strategy tries to understand the impact of building, or of not building, and to address the environmental, ecological, cultural, economic, and financial issues of a place.
Even after differentiating the terms, using ‘green’ and ‘sustainable’ interchangeably isn't necessarily a bad thing. Making a commitment to sustainability as big picture strategy for conscious design and building and living is the important takeaway.
Image: Lineal Inc.