While the proponents of "green" and sustainable construction struggle to come up with a comprehensive definition for the process of building in a way that's healthier for the earth and its inhabitants in the long run, the people who are actually buying houses seem to have come up with their own two-word definition, and it's not "carbon footprint."

Try "energy efficiency." That much more immediate and tangible outcome of green construction is what really has suddenly stoked folks' interest in green construction, not so much concerns over the longer-term effects of natural resource depletion.

Here's evidence:

For the first time, J.D. Power and Associates surveyed buyers of new construction about the "green" features of their homes, and out of a long list of "green" features with which they were presented, respondents selected energy-efficient heating and air-conditioning units, energy-saving appliances, energy-saving lighting, and temperature-controlling windows as the most important.

Of course, this really isn't rocket science. Those items have a direct impact on monthly bills, and, let's face it, that's going to rank higher on most homeowners' list of worries than whether or not the wood flooring came from a forest that's being managed in a sustainable way.

While the J.D. Power study probably targets more average buyers of newly constructed homes, there's some evidence to suggest that higher-end buyers care a lot about energy conservation in their homes as well. The American Institute of Architects (AIA) quarterly design trend survey shows a marked increase in requests from architectural clients for some very un-sexy elements in their homes–insulation, for example.

Demand for alternative insulation, such as spray foam and structural insulated panels, is up to 69 percent from 62 percent last year. And the demand for extra insulation has jumped even higher, from 56 percent to 68 percent.

Tankless hot water heaters are hot, up to 88 percent from 72 percent. Water-saving products jumped to 62 percent from 47 percent.

While it's clear that immediate monetary savings weigh heavily on consumers' minds, that doesn't mean they don't care about using products that will be good for the environment overall as well.

AIA survey respondents also say they see strong demand for "green" flooring, solar panels, and geothermal heating and cooling.

What's less clear is whether or not buyers are willing to pay more for products that might not cut operation costs but are more environmentally sound.

–Teresa Burney