AS COSTS HAVE RISEN IN ALL AREAS, LIFE-CYCLE COST ANALYSIS HAS BECOME INCREASINGLY IMPORTANT DURING FACILITY DESIGN AND PLANNING. THIS ANALYSIS IS A TECHNIQUE WHICH ASSESSES A GIVEN SOLUTION OR CHOICE BY CONSIDERING ALL RELEVANT ECONOMIC CONSEQUENCES OVER A GIVEN PERIOD OF TIME (OR 'LIFE-CYCLE'). THE GUIDE EXPLAINS CONCEPTS USED IN LIFE-CYCLE COST ANALYSIS SUCH AS TODAY DOLLARS, TOMORROW DOLLARS, AND DISCOUNT RATES. IT OUTLINES THE BASIC PROCEDURES AND RELATES THE ANALYSIS TO THE PLANNING AND DESIGN PROCESS. A BASIC TIME VOCABULARY FOR A LIFE-CYCLE COST ANALYSIS IS PRESENTED THAT INCLUDES A BASELINE DATE (A STARTING POINT), A TIME HORIZON (A CUTOFF POINT), AND A LIFE CYCLE (THE ELAPSED TIME BETWEEN THE BASELINE DATE AND TIME HORIZON). QUESTIONS OF WHAT COST CATEGORIES CAN BE INCLUDED IN A LIFE-CYCLE COST ANALYSIS AND METHODS FOR DETERMINING WHICH CATEGORIES TO USE ARE DISCUSSED. TWO COMMONLY USED MEASURES, THE TOTAL PRESENT WORTH COST AND THE EQUIVALENT UNIFORM ANNUAL COST, ARE PRESENTED AND EVALUATED. OTHER SECTIONS CONTAIN A STANDARD LIFE-CYCLE COST ANALYSIS FORMAT THAT INCLUDES FACTORS OF INFLATION AND UNCERTAINTY AND DESCRIBE MORE WAYS OF USING THE ANALYSIS, SUCH AS THE RATE OF RETURN ON INVESTMENT. A FINAL SECTION ASSESSES THE MEANING OF THE TECHNIQUE FOR ARCHITECTS AND ARCHITECTURAL PRACTICE. A GLOSSARY, REPRESENTATIVE DISCOUNT TABLES, AND ADDITIONAL SOURCES OF INFORMATION, AND TABULAR DATA ARE INCLUDED. (AOP)