A recent New York Times profile of architect Roald Gundersen, the founder of Wisconsin-based Whole Trees Architecture, left me reflecting on the meaning of sustainable building in the early 21st century.

In the context of U.S. residential building, sustainability tends to mean (to imply, that is) LEED-certified: the tiered certification process of the U.S. Green Building Council. This correlation restricts, I think, the meaning of "green homes" and sustainability more generally. The USGBC's LEED standards foreground materials (like energy-efficient appliances and bamboo flooring) rather than aesthetic design principles or structural elements (like building scale, supports, and foundation). Put differently, a LEED-certified structure is often identical in size, shape, design, and cost to a conventional home in a master-planned community; the primary differences are often, although certainly not always, invisible from the exterior (see figure 1).

A wave of experimental, and often non-profit (or minimally profitable), architects are rethinking this model of sustainable habitat. I commented in an earlier post on New York-based nonprofit Terreform 1, whose "ecological designs" are conceptual, futuristic, and profoundly computer-aided.

By comparison, Whole Trees Architecture is constructing inexpensive homes and buildings from thinned, felled, and damaged trees. Some of these houses even use small whole trees as curved supports, which can hold more weight than an equivalent volume of lumber beams and which continue to function as carbon sinks. In terms of both scale and cost, Whole Trees' projects depart from habituated ideas of an American home—whether green or not (see figures 2-3). The homes also offer an alternative aesthetic model of sustainable construction, one with roots in organic architecture. But, I would suggest that the structure and scale of such dwellings are more significant, and potentially transformational, in terms of how we define sustainability for the next century.