THE GUIDE EXPLAINS THE USE OF LIFE-CYCLE COSTING ANALYSIS TO EVALUATE AND RANK THE COST EFFECTIVENESS OF ALTERNATIVE ENERGY CONSERVATION RETROFIT PROJECTS TO EXISTING PUBLIC BUILDINGS AND TO SELECT THE MOST COST-EFFECTIVE DESIGN FOR NEW BUILDINGS. THE LCC ANALYSIS IS A METHOD OF ECONOMIC EVALUATION OF ALTERNATIVES WHICH CONSIDERS ALL RELEVANT COSTS (AND BENEFITS) ASSOCIATED WITH EACH ALTERNATIVE ACTIVITY OR PROJECT OVER ITS LIFE. IT PROVIDES AN EVALUATION OF THE NET EFFECT, OVER TIME, OF REDUCING FUEL COSTS BY PURCHASING, INSTALLING, MAINTAINING, OPERATING, REPAIRING, AND REPLACING ENERGY-CONSERVING FEATURES. ITS MAJOR STEPS ARE (1) IDENTIFICATION OF ALTERNATIVE ENERGY APPROACHES AND OF CONSTRAINTS THAT MUST BE IMPOSED SUCH AS LEVEL OF THERMAL COMFORT REQUIRED; (2) ESTABLISHMENT OF A COMMON TIME BASIS FOR EXPRESSING LCC VALUES, OF AN ANALYSIS STUDY PERIOD, AND OF THE ECONOMIC LIVES OF MAJOR ASSETS; (3) IDENTIFICATION AND ESTIMATION OF COSTS AND BENEFITS OF PARAMETERS TO BE CONSIDERED; (4) CONVERSION OF COSTS AND SAVINGS OCCURRING AT DIFFERENT TIMES TO A COMMON TIME; (5) COMPARISON OF INVESTMENT ALTERNATIVES, IN TERMS OF THEIR RELATIVE ECONOMIC EFFICIENCIES, IN ORDER TO SELECT THE ENERGY CONSERVATION PROJECTS THAT WILL RESULT IN THE LARGEST SAVINGS OF NONRENEWABLE ENERGY COSTS POSSIBLE FOR A GIVEN BUDGET AND CONSTRAINTS; AND (6) ANALYSIS OF THE RESULTS FOR SENSITIVITY TO THE INITIAL ASSUMPTIONS. WORKSHEETS, ILLUSTRATED WITH A REALISTIC EXAMPLE, AND A COMPUTER PROGRAM ARE PROVIDED IN THE GUIDE. THE GUIDE IS COMPATIBLE WITH A LIFE-CYCLE COSTING GUIDE PREPARED FOR THE DEPARTMENT OF ENERGY FOR USE IN THE FEDERAL ENERGY MANAGEMENT PROGRAM, AND IS MEANT AS AN AID FOR STATE AND LOCAL GOVERNMENTS FOR USE IN ENERGY CONSERVATION PROGRAMS. TABLES, FIGURES, A GLOSSARY, AND REFERENCES ARE PROVIDED. (AUTHOR ABSTRACT MODIFIED--DOC)