In the construction industry, the most eco-friendly type of building used to be LEED certified. That’s where buildings get different ratings according to how well they conserve energy and other resources. 

But today, there’s a higher standard — the living building — which is meant to be so green it actually leaves the environment better than it found it. Western Massachusetts may soon be one of the densest spots for this kind of project. But there are skeptics, including in the green building movement, who wonder whether pursuing such an environmental ideal, building by building, will ultimately serve the cause.