Chances are you know how
many miles your car logs for each gallon or tankful of gas, but you probably
have only a foggy idea of how much energy your house consumes, even though home
energy expenditures often account for a larger share of the household budget.
This disparity in useful
energy data is just one of several information gaps that must be bridged as the
United States transitions towards residences that generate as much energy as
they use over the course of a year—so-called net-zero houses.