A truly “carbon neutral” or “zero energy” building creates as much energy as it consumes on an annual basis. But a measurement of the carbon footprint of a building should also take into account the energy used to build it and maintain it. The task is daunting, both to measure and to achieve.

Construction expends a great deal of energy. That energy expenditure can be reduced by hiring builders who live near the site and by using recycled, local materials. The energy required to maintain a building can be decreased by utilizing materials that are long-lasting and low-maintenance.

Operational energy can be reduced with methods like tight construction and earth berming, an can even involve “turning the power meter backwards” - offsetting the energy consumed in the building’s construction, maintenance and operation by creating mechanical systems that produce energy, such as photovoltaic solar systems and wind turbines.