Found here: http://www.p4sc.org/articles/all/dua...ding-standards
"[New Urbanist co-founder Andres Duany] said that high-density development in urban locations which entail less reliance on private cars should get a free pass on energy efficiency or energy generation standards. "Don't make apartment dwellers install solar power," he said. "They are doing their part just by living densely and driving less."
He ridiculed the notion that single-family homes would ever lose popularity or that they should be squeezed out by public policy. But he did suggest that they be subject to more efficiency requirements to compensate for the inherent inefficiency of this use of land."
From what I've read, this idea also goes hand-in-hand with Ed Glaeser's ideas in his new book that building and living in dense urban areas is already the "greenest" thing humans can do.