1、Designation: E917 15Standard Practice forMeasuring Life-Cycle Costs of Buildings and BuildingSystems1This standard is issued under the fixed designation E917; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONSeveral methods of economic evaluation are available to measure the economic performance of abuilding or building system over a sp
3、ecified time period. These methods include, but are not limitedto, life-cycle cost (LCC) analysis, the benefit-to-cost ratio, internal rate of return, net benefits,payback, multiattribute decision analysis, risk analysis, and related measures (see Practices E964,E1057, E1074, E1121, E1765, and E1946
4、). These methods differ in their measure and, to some extent,in their applicability to particular types of problems. Guide E1185 directs you to the appropriatemethod for a particular economic problem. One of these methods, life-cycle cost (LCC) analysis, isthe subject of this practice. The LCC metho
5、d sums, in either present-value or annual-value terms, allrelevant costs associated with a building or building system over a specified time period. Alternative(mutually exclusive) designs or systems for a given functional requirement can be compared on thebasis of their LCCs to determine which is t
6、he least-cost means of satisfying that requirement over aspecified study period.1. Scope1.1 This practice establishes a procedure for evaluating thelife-cycle cost (LCC) of a building or building system andcomparing the LCCs of alternative building designs or systemsthat satisfy the same functional
7、requirements.1.2 The LCC method measures, in present-value or annual-value terms, the sum of all relevant costs associated withowning and operating a building or building system over aspecified time period.1.3 The basic premise of the LCC method is that to aninvestor or decision maker all costs aris
8、ing from an investmentdecision are potentially important to that decision, includingfuture as well as present costs.Applied to buildings or buildingsystems, the LCC encompasses all relevant costs over adesignated study period, including the costs of designing,purchasing/leasing, constructing/install
9、ing, operating,maintaining, repairing, replacing, and disposing of a particularbuilding design or system.1.4 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not
10、considered standard.2. Referenced Documents2.1 ASTM Standards:2E631 Terminology of Building ConstructionsE833 Terminology of Building EconomicsE964 Practice for Measuring Benefit-to-Cost and Savings-to-Investment Ratios for Buildings and Building SystemsE1057 Practice for Measuring Internal Rate of
11、Return andAdjusted Internal Rate of Return for Investments inBuildings and Building SystemsE1074 Practice for Measuring Net Benefits and Net Savingsfor Investments in Buildings and Building SystemsE1121 Practice for Measuring Payback for Investments inBuildings and Building SystemsE1185 Guide for Se
12、lecting Economic Methods for Evaluat-ing Investments in Buildings and Building SystemsE1369 Guide for Selecting Techniques for Treating Uncer-tainty and Risk in the Economic Evaluation of Buildingsand Building SystemsE1765 Practice for Applying Analytical Hierarchy Process(AHP) to Multiattribute Dec
13、ision Analysis of Investments1This practice is under the jurisdiction of ASTM Committee E06 on Perfor-mance of Buildings and is the direct responsibility of Subcommittee E06.81 onBuilding Economics.Current edition approved Oct. 1, 2015. Published October 2015. Originallyapproved in 1983. Last previo
14、us edition approved in 2013 as E917 13. DOI:10.1520/E0917-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.
15、Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1Related to Buildings and Building SystemsE1946 Practice for Measuring Cost Risk of Buildings andBuilding Systems and Other Constructed ProjectsE2204 Guide for Summarizing the Economic Im
16、pacts ofBuilding-Related Projects2.2 Adjuncts:Discount Factor Tables Adjunct to Practices E917, E964,E1057, E1074, and E112133. Terminology3.1 DefinitionsFor definitions of general terms related tobuilding construction used in the practice, refer to TerminologyE631; and for general terms related to
17、building economics,refer to Terminology E833.4. Summary of Practice4.1 This practice outlines the recommended procedures forcomputing the LCCs associated with a building or buildingsystem over a specified time period. It identifies and givesexamples of objectives, alternatives, and constraints for a
18、nLCC analysis; identifies project data and general assumptionsneeded for the analysis; and presents alternative approaches forcomputing LCCs. This practice requires that the LCCs ofalternative building designs or systems be compared over acommon time period to determine which design or system hasthe
19、 lowest LCC. This practice also states that uncertainty,unquantifiable effects, and funding constraints shall be consid-ered in the final analysis. It identifies the recommendedcontents of an LCC report, describes proper applications of theLCC method, provides examples of its use, and identifieslimi
20、tations of the method. A comprehensive example of theLCC method applied to a building economics problem isprovided in Appendix X1. A comprehensive example illustrat-ing the treatment of uncertainty within the LCC method isprovided in Appendix X2. Appendix X3 provides a detailedexample analyzing the
21、life-cycle cost implications resultingfrom energy efficiency improvements in a high school building.Appendix X4 provides a description of the Adjunct.5. Significance and Use5.1 LCC analysis is an economic method for evaluating aproject or project alternatives over a designated study period.The metho
22、d entails computing the LCC for alternative buildingdesigns or system specifications having the same purpose andthen comparing them to determine which has the lowest LCCover the study period.5.2 The LCC method is particularly suitable for determiningwhether the higher initial cost of a building or b
23、uilding systemis economically justified by reductions in future costs (forexample, operating, maintenance, repair, or replacement costs)when compared with an alternative that has a lower initial costbut higher future costs. If a building design or system specifi-cation has both a lower initial cost
24、and lower future costsrelative to an alternative, an LCC analysis is not needed toshow that the former is the economically preferable choice.5.3 If an investment project is not essential to the buildingoperation (for example, replacement of existing single-panewindows with new double-pane windows),
25、the project must becompared against the “do nothing” alternative (that is, keepingthe single pane windows) in order to determine if it is costeffective. Typically the “do nothing” alternative entails noinitial investment cost but has higher future costs than theproposed project.6. Procedure6.1 Follo
26、w these steps in calculating the LCC for a buildingor building system:6.1.1 Identify objectives, alternatives, and constraints (seeSection 7).6.1.2 Establish basic assumptions for the analysis (see 8.1).6.1.3 Compile cost data (see 8.2).6.1.4 Compute the LCC for each alternative (see Section 9).6.1.
27、5 Compare LCCs of each alternative to determine theone with the minimum LCC (see 10.1).6.1.6 Make final decision, based on LCC results as well asconsideration of risk and uncertainty, unquantifiable effects,and funding constraints (if any) (see 10.2, 10.3, 10.4, and 10.5).7. Objectives, Alternatives
28、, and Constraints7.1 Specify the design or system objective that is to beaccomplished, identify alternative designs or systems thataccomplish that objective, and identify any constraints thatlimit the available options to be considered.7.2 An example is the selection of a space heating systemfor a n
29、ew house. The system must satisfy the thermal comfortrequirements of the occupants throughout the heating season.Available alternatives (for example, various gas furnaces, oilfurnaces, heat pumps, and electric baseboard heaters) may havedifferent types of fuel usage with different unit costs, differ
30、entfuel conversion efficiencies, different initial costs and expectedmaintenance and repair costs, and different lives. Systemselection will be constrained to those fuel types available at thebuilding site.8. Data and Assumptions8.1 Basic AssumptionsEstablish the uniform assumptionsto be made in the
31、 economic analysis of all alternatives. Theseassumptions usually include, but are not limited to, theconsistent use of the present-value or annual-value calculationmethod, the base time and study period, the general inflationrate, the discount rate, the marginal income tax rate (whererelevant), the
32、comprehensiveness of the analysis, and theoperational profile of the building or system to be evaluated.8.1.1 Present-Value Versus Annual-Value CalculationsThe LCCs of project alternatives must be calculated uniformlyin present-value or annual-value terms. In the former, all costsare discounted to t
33、he base time; in the latter, all costs areconverted to a uniform annual amount equivalent to the presentvalue when discounted to the base time.8.1.2 Study PeriodThe study period appropriate to theLCC analysis may or may not reflect the life of the building orsystem to be evaluated.The same study per
34、iod must be used foreach alternative when present-value calculations are used. An3Available from ASTM International Headquarters. Order Adjunct No.ADJE091703. Original adjunct produced in 1984. Adjunct last revised in 1985.E917 152annual-value LCC may, under certain restrictive assumptions,be used t
35、o compare alternatives with different study periods(see 9.2.3). The following guidelines may be useful forselecting a study period for an LCC analysis:8.1.2.1 When analyzing a project from an individual inves-tors standpoint, the study period should reflect the investorstime horizon. For a homeowner
36、, the study period for ahouse-related investment might be based on the length of timethe homeowner expects to reside in the house. For a commer-cial property owner, the study period might be based on theanticipated holding period of the building. For an owner/occupant of a commercial building, the s
37、tudy period mightcorrespond to the life of the building or building system beingevaluated. For a speculative investor, the study period might bebased on a relatively short holding period. For investments bygovernment agencies and large institutions, specific internalpolicies often direct the choice
38、of study period.8.1.2.2 When LCC analyses of alternative building systemsor design practices are performed for general informationrather than for a specific application (for example, governmentor industry research to determine the cost effectiveness ofthermal insulation or high-efficiency heating an
39、d coolingequipment in typical installations), the study period will oftencoincide with the service life of the material or system (but belimited to the typical life of the type of building where it is tobe installed). When the service life is very long, a moreconservative choice for the study period
40、 might be used if theuncertainty associated with the long-term forecasting of costssubstantially reduces the credibility of the results.8.1.2.3 Regardless of the type of investor or purpose of theanalysis, use the same study period for all categories of costswhen calculating the present value of any
41、 cost associated witha project. Furthermore, when comparing alternative designs orsystems on the basis of their present-value LCCs, use the samestudy period for each investment alternative.8.1.2.4 When the study period selected is significantlyshorter than the service life of the building or system
42、evaluated,it is important that a realistic assessment of the projects resale(or residual) value at the end of the study period be included inthe LCC analysis. Even if the building will not be sold at thattime, the resale value will likely have a significant impact onthe LCC.8.1.3 InflationGeneral pr
43、ice inflation is the reduction inthe purchasing power of the dollar from year to year, asmeasured, for example, by the percent increase in the grossnational product (GNP) deflator over a given year. LCCanalyses can be calculated in constant-dollar terms (net ofgeneral inflation) or in current-dollar
44、 terms (including generalinflation). If the latter is used, a consistent projection of generalprice inflation must be used throughout the LCC analysis,including adjustment of the discount rate to incorporate thegeneral inflation rate.8.1.3.1 When income tax effects are not included in theLCC analysi
45、s, as in the case of LCC evaluations of nonprofitbuildings and owner-occupied houses (without financing), it isusually easier to express all costs in constant dollars. Pricechanges for individual cost categories that are higher or lowerthan the rate of general inflation can be included by usingdiffe
46、rential rates of price change for those categories.8.1.3.2 When income tax effects are included in the LCCanalysis, it is usually easier to express all costs in currentdollars because income taxes are tied to current-dollar cashflows rather than constant-dollar cash flows.8.1.4 Discount RateThe disc
47、ount rate selected shouldreflect the investors time value of money. That is, the discountrate should reflect the rate of interest that makes the investorindifferent between paying or receiving a dollar now or at somefuture point in time. The discount rate is used to convert costsoccurring at differe
48、nt times to equivalent costs at a commonpoint in time.8.1.4.1 Select a discount rate equal to the rate of return onthe next best available use of funds. Where the discount rate islegislated or mandated for a given institution, that rate takesprecedence.8.1.4.2 A discount rate that includes general p
49、rice inflationover the study period is referred to as the “nominal” discountrate in this practice. A discount rate expressed in terms net ofgeneral price inflation is referred to as the “real” discount rate.8.1.4.3 Anominal discount rate, i, and its corresponding realdiscount rate, r, are related as follows:r 511i11I2 1ori 5 11r!11I! 2 1 (1)where:I = the rate of general price inflation.8.1.4.4 Use a real discount rate if estimates of future costsare expressed in constant dollars, that is, if they do not includegeneral inflation.8.1.4.5 Use a nominal discount rate if esti
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