(a)
be based on up-to-date, measured, traceable operational data on energy consumption and (for electricity) load profiles;
(b)
comprise a detailed review of the energy consumption profile of buildings or groups of buildings, industrial operations or installations, including transportation;
(c)
build, whenever possible, on life-cycle cost analysis (LCCA) instead of Simple Payback Periods (SPP) in order to take account of long-term savings, residual values of long-term investments and discount rates;
(d)
be proportionate, and sufficiently representative to permit the drawing of a reliable picture of overall energy performance and the reliable identification of the most significant opportunities for improvement.