Measurement and verification (M&V) is the process of using measurements to reliably determine savings resulting from an energy management program. Savings cannot be directly measured, since they represent the absence of energy use. Instead, savings are determined by comparing measured use before and after project implementation, with appropriate adjustments for changes in conditions. The IPMVP provides methods, with different levels of cost and accuracy, for determining savings, either for the whole facility or for individual energy conservation measures (ECM).