Economic efficiency is one of the three aspects of a sustainable practice. There are several concepts that relate to the economics of sustainability.
Focus on Reducing Waste
Making processes more efficient means reducing the amount of waste involved in the production of an outcome. For example, one of the most significant improvements in waste reduction in building systems is the advance from old fluorescent lighting systems to new. The new technology produces brighter light and uses less electrical power. Another example of efficiency is the introduction of occupancy sensors. A common obstacle to reducing wasted energy is lights being left on when there are no occupants. Occupancy sensors turn lights off when no occupants are detected.
Life Cycle Perspective
Use of life cycle cost analyses go hand in hand with sustainable practices. Instead of only considering the near term impact of cost decisions, "first cost," the entire life of the project should be considered. This is very challenging when tight budgets constrain the inclusion of desirable project features. First costs are important, however, all costs associated with the entire life of the project must also be considered. For example, building project costs can be reduced if less insulation is used. At some point, however, the initial savings will be outpaced by the higher operating costs of the faciity.
Triple Bottom Line (TBL) Accounting
This term refers to economic accounting based on the three principles of sustainability - economic, environmental, and social performance.