If the purpose of an LCC analysis is primarily to evaluate the energy savings for a particular building or building system, the analysis should be conducted using the FEMP LCC criteria according to 10 CFR 436A. An analysis that evaluates two different buildings or building systems being considered for the same use, both incorporating approximately the same degree of energy or water conservation in design and using approximately the same amount of energy (so that the purpose of the evaluation is not primarily to assess energy-related savings) should be conducted using the criteria and discount rates specified in OMB Circular A-94.
However, if a project involves energy usage only peripherally, and the energy-related and non-energy-related parts of the investment cannot be broken out, the decision as to whether to use the criteria of OMB Circular A-94 or the FEMP criteria is left to the judgment of the analyst.
Water resource projects are subject to Economic and Environmental Principles and Guidelines for Water and Related Land Resources Implementation Studies.