Changes in household size and home construction have been the main causes of over-consumption of energy by American consumers, according to a new study released by SMR Research Corporation.

A reversal of these trends, SMR noted, would dramatically reduce U.S. energy use. Yet, household demographics and home building are seldom mentioned in the debates over global warming and energy independence.

SMR's study, Consumer Energy Spending And The Demographics Of Over-Consumption, is based on detailed interviews with more than 27,000 households.

Single-person households, which have grown at triple the rate of overall population growth since 1960, use 18.4% more energy per capita than two-person households do, SMR found. They use 52.8% more energy per capita than three-person households.

Even when excluding households with children, since they do not drive, per-capita energy use is far higher among single-person households than any others, SMR found.