E1121 (version 15(2020)e1)

1.1 This practice provides a recommended procedure for calculating and applying the payback method in evaluating building designs and building systems.

1.2 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.