Salon.com has a great article that discusses the environmental impacts of building larger and larger houses. Apparently, even super-efficient, high-tech houses that use the latest in “green” construction techniques use more energy than smaller but less efficient homes. For example, a 1998 Environmental Building News article found that…

a 1,500-square-foot home with low energy performance standards will use less energy for heating and cooling than a 3,000-square-foot house with high energy performance standards.

And the long-term trends on house size are telling:

Fifty years ago, the average house size was 1,100 square feet, and the average household size was 4.2 people. Today, the average house size has increased to 2,150 square feet, while the average household size has declined to 2.3 people.

That means that, person for person, we have about three and a half times as much house as our grandparents did. To some extent, that’s a good thing, since older houses would probably feel cramped to many families today. But our love of elbow room carries an environmental toll: it means that our technology has to be three and a half times as efficient as our grandparents’ to provide the same level of comfort without increasing our energy consumption.

The trend towards ever-larger houses, packed with the latest in environmentally-friendly materials and super-efficient appliances, produces the most cogent line in the article:

“Give Americans sustainable technology, and we’ll super-size it beyond recognition.”