工程造價(jià)外文及翻譯

第第頁(yè)TheCostofBuildingStructure1.IntroductionTheartofarchitecturaldesignwascharacterizedasoneofdealingcomprehensivelywithacomplexsetofphysicalandnonphysicaldesigndeterminants.Structuralconsiderationswerecastasimportantphysicaldeterminantsthatshouldbedealtwithinahierarchicalfashioniftheyaretohaveasignificantimpactonspatialorganizationandenvironmentalcontroldesignthinking.Theeconomicalaspectofbuildingrepresentsanonphysicalstructuralconsiderationthat,infinalanalysis,mustalsobeconsideredimportant.Costconsiderationsareincertainwaysaconstrainttocreativedesign.Butthisneednotbeso.Ifsomethingisknownoftherelationshipbetweenstructuralandconstructivedesignoptionsandtheircostofimplementation,itisreasonabletobelievethatcreativitycanbeenhanced.Thishasbeenconfirmedbytheauthors’observationthatmostenhanced.Thishasbeenconfirmedbytheauthors’observationthatmostcreativedesigninnovationssucceedundercompetitivebiddingandnotbecauseofunusualowneraffluenceasthefewpublicizedcasesofextravagancemightleadonetobelieve.Onecouldevensaythatadesignerwhoistrulycreativewillproducearchitecturalexcellencewithintheconstraintsofeconomy.Especiallytoday,wefindthatthereisaneedtorecognizethateleganceandeconomycanbecomesynonymousconcepts.Therefore,inthischapterwewillsetforthabriefexplanationoftheparametersofcostanalysisandthemeansbywhichdesignersmayevaluatetheoveralleconomicimplicationsoftheirstructuralandarchitecturaldesignthinking.Thecostofstructurealonecanbemeasuredrelativetothetotalcostofbuildingconstruction.Or,sincethetotalconstructioncostisbutapartofatotalprojectcost,onecouldincludeadditionalconsiderationforland(10～20percent),financeandinterest(100～200percent),taxesandmaintenancecosts(ontheorderof20percent).Butadiscussionoftheseso-calledarchitecturalcostsisbeyondthescopeofthisbook,andwewillfocusonthecostofconstructiononly.Ontheaverage,purelystructuralcostsaccountforabout25percentoftotalconstructioncosts,Thisissobecauseithasbeentraditionaltodiscriminatebetweenpurelystructuralandotherso-calledarchitecturalcostsofconstruction.Thus,intraditionwefindthatarchitecturalcostshavebeentakentobethosethatarenotnecessaryforthestructuralstrengthandphysicalintegrityofabuildingdesign.“Essentialservices”formsathirdconstructioncostcategoryandreferstotheprovisionofmechanicalandelectricalequipmentandotherservicesystems.Ontheaverage,theseservicecostsaccountforsome15to30percentofthetotalconstructioncost,dependingonthetypeofbuilding.Mechanicalandelectricalreferstothecostofprovidingforair-conditioningequipmentandhemeansonairdistributionaswellasotherservices,suchasplumbing,communications,andelectricallightandpower.Thesalientpointisthatthisbreakdownofcostssuggeststhat,uptonow,anaverageofabout45to60percentofthetotalcostofconstructingatypicaldesignsolutioncouldbeconsideredasarchitectural.Butthispictureisrapidlychanging.Withhighinterestcostsandascarcityofcapital,clientgroupsaredemandingleanerdesigns.Therefore,onemayconcludethattherearetwoapproachesthedesignermaytaketowardsinfluencingtheconstructioncostofbuilding.Thefirstapproachtocostefficiencyistoconsiderthatwhereverarchitecturalandstructuralsolutionscanbeachievedsimultaneously,apotentialforeconomyisevident.Sincecurrenttrendsindicateareluctancetoallocatelargeportionsofaconstructionbudgettopurelyarchitecturalcosts,thisapproachseemsalogicalnecessity.But,evenwheremoneyisavailable,anyuseofstructuretoplayabasicarchitecturalrolewillallowthenonstructuralbudgettobeappliedtofulfillotherarchitecturalneedsthatmightnormallyhavetobeappliedtofulfillotherarchitecturalneedsthatmightnormallyhavetobecutback.Thesecondapproachachieveseconomythroughanintegrationofserviceandstructuralsubsystemstoroundoutone’sefforttoproduceatotalarchitecturalsolutiontoabuildingdesignproblem.Thefinalpricingofaprojectbytheconstructororcontractorusuallytakesadifferentform.Thecostsarebrokendowninto(1)costofmaterialsbroughttothesite,(2)costoflaborinvolvedineveryphaseoftheconstructionprocess,(3)costofequipmentpurchasedorrentedfortheproject,(4)costofmanagementandoverhead,and(5)profit.Thearchitectorengineerseldomfollowssuchanaccuratepathbutshouldperhapskeepinmindhowtheactualcostofastructureisfinallypricedandmadeup.Thus,thepercentaveragesstatedaboveareobviouslycrude,buttheycansufficetointroducethenatureofthecostpicture.Thefollowingsectionswilldiscusstherangeoftheseaveragesandthenproceedtoadiscussionofsquarefootagecostsandabove.Atbest,thiswillbeacrudemeasure,butitishopedthatthereaderwillfindthatitmakeshimsomewhatfamiliarwiththetypeofrealeconomicproblemsthatresponsibledesignersmustdealwith.Attheleast,thiscapabilitywillbeusefulincomparingalternativesystemsforthepurposeofdeterminingtheirrelativecostefficiency.3.Square-footEstimatingAsbefore,itispossibletoempiricallydeterminea“standard”per-square-footcostfactorbasedontheaverageofcostsforsimilarconstructionatagivenplaceandtime.more-or-lessefficientdesignsarepossible,dependingontheabilityofthedesignerandcontractortousematerialsandlaborefficiently,andvaryfromtheaverage.Therangeofsquare-footcostsfor“normal”structuralsystemsis﹩10to﹩16psf.Forexample,typicalofficebuildingsaveragebetween﹩12and﹩16psf,andapartment-typestructuresrangefrom﹩10to﹩14.Ineachcase,thelowerpartoftherangereferstoshortspansandlowbuildings,whereastheupperportionreferstolongerspansandmoderatelytallbuildings.Ordinaryindustrialstructuresaresimpleandnormallyproducesquare-footcostsrangingfrom﹩10to﹩14,aswiththemoretypicalapartmentbuilding.Althoughthespansforindustrialstructuresaregenerallylongerthanthoseforapartmentbuildings,andtheloadsheavier,theycommonlyhavefewercomplexitiesaswellasfewerinteriorwalls,partitions,ceilingrequirements,andtheyarenottall.Inotherwords,simplicityofdesignanderectioncanoffsettheadditionalcostforlongerspanlengthsandheavierloadsinindustrialbuildings.Ofcoursethereareexceptionstotheseaverages.Thelimitsofvariationdependonasystem’scomplexity,spanlengthover“normal”andspecialloadingorfoundationconditions.Forexample,theCrownZellerbachhigh-risebankandofficebuildinginSanFranciscoisanexception,sinceitsstructuralcostswereunusuallyhigh.However,inthiscase,theuseof60ftsteelspansandfree-standingcolumnsatthebottom,whichcarrytheconsiderableearthquakeloading,aswellasthespecialfoundationassociatedwiththepoorSanFranciscosoilconditions,contributedtotheexceptionallyhighcosts.Thedesignwasalsounusualforitstimeandadecisionhadbeenmadetoallowhigherthannormalcostsforallaspectsofthebuildingtoachieveopenspacesandforbothfunctionandsymbolicreasons.Hencetheproportionofstructuraltototalcostprobablyremainedsimilartoordinarybuildings.Theeffectofspanslongerthannormalcanbefurtherillustrated.The“usual”floorspanrangeisasfollows:forapartmentbuildings,16to25ft;forofficebuildings,20to30ft;forindustrialbuildings,25to30ftloadedheavilyat200to300psf;andgarage-typestructuresspan,50to60ft,carryingrelativelylight(50～75psf)loads(i.e.,similartothoseforapartmentandofficestructures).wherethesespansaredoubled,thestructuralcostscanbeexpectedtoriseabout20to30percent.Toincreasedloadinginthecaseofindustrialbuildingsoffersanotherinsightintothedependencyofcostestimateson“usual”standards.Iftheloadinginanindustrialbuildingweretobeincreasedto500psf(i.e.,twoorthreetimes),theadditionalstructuralcostwouldbeontheorderofanother20to30percent.Thereferenceintheabovecasesisforfloorsystems.Forroofsusingefficientorthotropic(flat)systems,contemporarylimitsforeconomicaldesignappeartobeontheorderof150ft,whetherofsteelorprestressedconcrete.Althoughspace-framesareoftenusedforsteelorprestressedconcrete.Althoughspace-framesareoftenusedforsteelspansover150ftthefabricationcostsbegintoraiseconsiderably.Atanyrate,itshouldberecognizedthatverylong-spansubsystemsarespecialcasesandcaninthemselveshaveagreatorsmalleffectonisadded,structuralcostsforspecialbuildingscanvarygreatlyfromdesigntodesign.Themorespecialtheform,themorethatdesignknowledgeandcreativity,aswellasconstructionskill,willdeterminethepotentialforachievingcostefficiency.4.Volume-BasedEstimatesWhenmoreaccuracyisdesired,estimatesofcostscanbebasedonthevolumeofmaterialsusedtodoajob.Atfirstglanceitmightseemthatthearchitectwouldbeillequippedtoestimatethevolumeofmaterialrequiredinconstructionwithanyaccuracy,andmuchlessspeed.Butitispossible,withamoderatelearningeffort,toachievesomecapabilityformakingsuchestimates.Volume-basedestimatesaregivenbyassigningin-placevaluetothepoundsortonsofsteel,orthecubicyardsofreinforcedorprestressedconcreterequiredtobuildastructuralsystem.Forsuchapreliminaryestimate,onedoesnotneedtoitemizedetailedcosts.Forexample,in-placeconcretecostsincludethecostofforming,falsework,reinforcingsteel,labor,andoverhead.Steelincludesfabricationanderectionofcomponents.Costsofstructuralsteelasmeasuredbyweightrangefrom﹩0.50to﹩0.70perpoundinplaceforbuildingconstruction.Forlow-risebuildings,onecanusestockwide-flangestructuralmembersthatrequireminimumfabrication,andthecostcouldbeasbowas﹩0.50perpound.Morecomplicatedsystemsrequiringmuchcuttingandwelding(suchasacomplicatedsteeltrussorspace-framedesign)cangoto﹩0.70perpoundandbeyond.Forstandardtallbuildingdesigns(say,exceeding20stories),therewouldtypicallybeabout20to30poundsofsteel/psf,whichoneshouldwishnottoexceed.Adesigncallingforunder20psfwouldrequireagreatdealofingenuityandthecarefulintegrationofstructuralandarchitecturalcomponentsandwouldbearealaccomplishment.Concretecostsarevolumetricandshouldrangefromanin-placelowof﹩150percuydforverysimplereinforcedconcreteworkto﹩300percuydforexpensivesmallquantityprecastandprestressedwork.Thislargerangeisduetothefactthatthecontributingvariablesaremorecomplicated,dependingupontheshapeoftheprecisecomponents,theerectionproblems,andthetotalquantityproduced.Formworkisgenerallythecontrollingfactorforanycast-in-placeconcretework.Therefore,toachieveacostof﹩150percuyd,onlythesimplestofsystemscanbeused,suchasflatslabsthatrequirelittlecuttingandmuchreuseofforms.Whereanybeamsareintroducedthatrequirespecialformsanddifficultyinplacementofconcreteandsteelbars,therangebeginsat﹩180percuydandgoesupto﹩300.Since,inadevelopedcountry,highlaborcostsaccountforhighformingcosts,thisresultsinpressuretousethesimplestandmostrepetitiveofsystemstokeepcostsdown.Itbecomerewardingtoconsiderthepossibilityofmass-producedprecastandprestressedcomponents,whichmaybringasavingincostsand\orconstructioncompletiontime.Thelatterresultsinsavingsduetolowerconstructionfinancingcostsforthecontractorplusquickerearningsfortheowner.Tosummarize,therangeofcostpercubicyardofstandardtypesofpoured-in-placeconcreteworkwillaveragefrom$150to$250,theminimumbeingforsimplereinforcedworkandthemaximumformoderatelycomplicatedposttensionedwork.Thisrangeislargeandanyestimatethatignorestheeffectofvariablesabovewillbecommensuratelyinaccurate.5.SummaryTheestimateandeconomicaldesignofstructurebuildingareimportantandessentialwork,whichshouldbevaluedbyallarchitectsandengineersandothers.Betteryoudoit,moreprofityouwillreceivefromit!建筑結(jié)構(gòu)的成本1.前言眾所周知，建筑物的結(jié)構(gòu)設(shè)計(jì)是一個(gè)相當(dāng)復(fù)雜的過(guò)程，其中既包含處理很多物質(zhì)因素，又考慮諸多非物質(zhì)方面的因素。如果建筑物的結(jié)構(gòu)形式對(duì)空間組織和美化環(huán)境的設(shè)計(jì)起這句舉足輕重的影響，那么它就是一個(gè)相當(dāng)重要的物理因素，就應(yīng)當(dāng)采用分階段的設(shè)計(jì)方法。對(duì)建筑物的經(jīng)濟(jì)考慮是一個(gè)主要的非物質(zhì)因素，在最終的設(shè)計(jì)中應(yīng)予以重視。對(duì)一個(gè)具有創(chuàng)造性的設(shè)計(jì)而言，經(jīng)濟(jì)考慮從某方面來(lái)說(shuō)往往是一種制約，但這也并非是絕對(duì)的。如果事先清楚結(jié)構(gòu)設(shè)計(jì)及施工組織方案與實(shí)現(xiàn)他們的造價(jià)之間的關(guān)系，那么創(chuàng)造性是同樣可以實(shí)現(xiàn)的。調(diào)查表明，大多具有創(chuàng)造性的設(shè)計(jì)是在有競(jìng)爭(zhēng)性的投標(biāo)中獲得成功的，而不是因?yàn)闃I(yè)主非常富有。盡管后者被大肆炒作，卻很少使人信服。因此也可以說(shuō)，真正具有創(chuàng)造性的設(shè)計(jì)因該具有很強(qiáng)的經(jīng)濟(jì)性。特別是今天，人們應(yīng)該逐漸認(rèn)識(shí)到，高雅和經(jīng)濟(jì)其實(shí)是一個(gè)可以統(tǒng)一的概念。因此，本文列舉一些造價(jià)分析參數(shù)的簡(jiǎn)單解釋，以及設(shè)計(jì)人員在他們的結(jié)構(gòu)設(shè)計(jì)中考慮經(jīng)濟(jì)因素是經(jīng)常采用的一些設(shè)計(jì)中考慮經(jīng)濟(jì)因素是經(jīng)常采用的一些設(shè)計(jì)手法。結(jié)構(gòu)造價(jià)本身是通過(guò)其在建筑物總造價(jià)中所占的百分比來(lái)衡量的?；蛘哒f(shuō)，由于工程只是一個(gè)項(xiàng)目總造價(jià)的一部分，因此還要考慮附加費(fèi)用如地價(jià)（10%~20%）、籌資利息（100%~200%）、稅金及維修費(fèi)（20%左右）。不過(guò)上面這些因素都不在本文的討論范圍之內(nèi)，文章將重點(diǎn)介紹工程造價(jià)。平均來(lái)說(shuō)，單純的結(jié)構(gòu)造價(jià)大約占建筑物總造價(jià)25%。按照慣例，建筑無(wú)的結(jié)構(gòu)造價(jià)和所謂的建筑造價(jià)是分開(kāi)的。一般說(shuō)來(lái)，所謂的建筑造價(jià)，往往是指那些與建筑的結(jié)構(gòu)強(qiáng)度和物理完整性無(wú)關(guān)的因素?！盎痉?wù)設(shè)施費(fèi)”組成了第三類工程費(fèi)用，主要是指機(jī)械供給、電器設(shè)備以及其他一些服務(wù)體系等費(fèi)用。一般說(shuō)來(lái)，這部分費(fèi)用大概占建筑物總費(fèi)用的15%~30%，這主要取決于建筑無(wú)的類型。機(jī)械和電氣費(fèi)用，主要是指空調(diào)系統(tǒng)費(fèi)用以及其他諸如管道系統(tǒng)、通訊、照明及動(dòng)力設(shè)備等其他服務(wù)設(shè)施。在這一造價(jià)分類中非常顯著的一點(diǎn)是，一個(gè)典型的建筑物設(shè)計(jì)方案的總體費(fèi)用，應(yīng)該有45%~60%分配給建筑因素。但現(xiàn)在這種狀況正在迅速改變，因?yàn)楦呃室约百Y金的缺乏，現(xiàn)在大多業(yè)主更傾向于節(jié)約型設(shè)計(jì)。因此，設(shè)計(jì)者應(yīng)該考慮兩條途徑，他們可以直接影響建筑無(wú)的工程造價(jià)。第一個(gè)節(jié)約開(kāi)支的途徑可以這樣來(lái)考慮，即凡是那些建筑問(wèn)題和結(jié)構(gòu)問(wèn)題能夠同時(shí)解決的地方往往有著很強(qiáng)的經(jīng)濟(jì)潛力。由于目前大多設(shè)計(jì)都不愿將建筑物費(fèi)用一大部分用于純粹建筑設(shè)計(jì)，這種方法就顯得尤為重要，也會(huì)節(jié)省一部分非結(jié)構(gòu)預(yù)算，這一經(jīng)費(fèi)可用于一些本會(huì)被削減掉的建筑需求。第二種節(jié)約開(kāi)支的途徑，則是設(shè)計(jì)人員在設(shè)計(jì)過(guò)程中綜合考慮服務(wù)設(shè)施和結(jié)構(gòu)體系，盡力提出一個(gè)能夠解決房屋設(shè)計(jì)和施工難題的總建筑方案。承包商通?；赜貌煌姆绞阶龀龉こ添?xiàng)目的最終報(bào)價(jià)。他們往往將其分為場(chǎng)地材料費(fèi)、每一個(gè)施工過(guò)程中的勞動(dòng)力資源費(fèi)、工程所需購(gòu)買、租借的裝備費(fèi)、經(jīng)營(yíng)管理費(fèi)以及利潤(rùn)。建筑師以及工程師很少考慮的像上面所述的那么精確，但是頭腦中應(yīng)該有一個(gè)清楚的概念，那就是一項(xiàng)結(jié)構(gòu)工程的實(shí)際造價(jià)最終使用什么方法定價(jià)以及承包商又是怎樣標(biāo)價(jià)的。顯然，上面講到的百分比平均數(shù)有些粗略，但是它足以說(shuō)明總體造價(jià)的組成情況了。下面的幾部分將討論這些平均數(shù)的范圍，并進(jìn)一步闡述在對(duì)建筑無(wú)的造價(jià)進(jìn)行粗略、近似估計(jì)時(shí)用到的平方英尺以及單位體積造價(jià)。2.百分比估價(jià)建筑物的類型將決定結(jié)構(gòu)費(fèi)用以及其他費(fèi)用所占的白分比范圍。正如所希望的，裝飾性或者標(biāo)志性較強(qiáng)的建筑物的結(jié)構(gòu)造價(jià)在總體造價(jià)中所占的比重相對(duì)較低。一般而言，結(jié)構(gòu)造價(jià)所占的百分比可低至工程總造價(jià)的10%~15%，這是因?yàn)楦嗟腻X被用到那些非結(jié)構(gòu)費(fèi)用上了。這又一次說(shuō)明“裝飾”部分是與基本的結(jié)構(gòu)要求無(wú)關(guān)的。然而對(duì)于一些諸如教堂類的綜合性標(biāo)志建筑物，對(duì)其結(jié)構(gòu)體系的造價(jià)相對(duì)較高，其百分比可達(dá)到15%~20%或者更高。與之相對(duì)的是一些諸如倉(cāng)庫(kù)或者車庫(kù)之類簡(jiǎn)易的和非象征性的工業(yè)建筑物，對(duì)于這種建筑，由于內(nèi)部隔墻、天花板、管道設(shè)備系統(tǒng)以及裝修部分要求較低，其結(jié)構(gòu)造價(jià)在工程總體造價(jià)中所占的比例往往能達(dá)到60%~70%，有時(shí)甚至可達(dá)80%。對(duì)于一些中等高度（5~10層）得多層辦公樓或住宅樓，其結(jié)構(gòu)造價(jià)在總體造價(jià)中所占的比例，大約維持在25%這一中間值；而對(duì)于一些低矮且跨據(jù)短的商業(yè)用房和住宅，大約3~4層高且跨度為20~30英尺以及簡(jiǎn)單的豎向要求，其結(jié)構(gòu)造價(jià)將占總造價(jià)15%~20%。而一些特殊用途的建筑，如實(shí)驗(yàn)室和醫(yī)院，則另當(dāng)別論。他們需要較大的跨度以及不一般要求高的機(jī)械裝備。這就導(dǎo)致總體造價(jià)得以大部分將被用于服務(wù)費(fèi)用（大約30%~50%）,而單純的結(jié)構(gòu)造價(jià)約占20%。對(duì)于15層或者以上的高層辦公樓以及大跨度（約50~60英尺）建筑物，其結(jié)構(gòu)造價(jià)在總體造價(jià)中將占較高的百分比（約30%~35%），而服務(wù)費(fèi)用約占30%~40%。在任何情況下這些百分比數(shù)據(jù)都是具有典型性的，并可作為衡量建筑物設(shè)計(jì)平均效益的尺度。例如，如果一個(gè)較低的小跨度且不具備紀(jì)念價(jià)值的建筑物，僅僅結(jié)構(gòu)造價(jià)投標(biāo)就為30%的話，那么可以肯定這個(gè)結(jié)構(gòu)設(shè)計(jì)是相當(dāng)不經(jīng)濟(jì)的。另一方面，建筑師應(yīng)該注意到的一個(gè)容易混淆的事實(shí)就是，經(jīng)濟(jì)投標(biāo)往往取決于設(shè)計(jì)者和承包人的理解設(shè)計(jì)及施工要求的實(shí)際能力，能力強(qiáng)就能提供一個(gè)較低的投標(biāo)。創(chuàng)造性設(shè)計(jì)受限往往是因?yàn)樵O(shè)計(jì)者或承包商在經(jīng)驗(yàn)、想象力際交流方面的匱乏。如果承包者沒(méi)有把握，那么它就會(huì)加大投資，以防可能遇到的意外風(fēng)險(xiǎn)。因此要使有創(chuàng)造性的設(shè)計(jì)在投標(biāo)時(shí)具有競(jìng)爭(zhēng)力，作為一名建筑師它應(yīng)能夠洞察工程潛力所在。至少建筑是應(yīng)該盡可能地與想象力豐富的結(jié)構(gòu)工程師、承包商甚至制造商驚醒密切配合。相反，即使對(duì)于最為普通的建筑設(shè)計(jì)，如果僅僅靠設(shè)計(jì)手冊(cè)，是很難取得經(jīng)濟(jì)效益的。效率離不開(kāi)專業(yè)知識(shí)，而最為重要的是想象力，這一點(diǎn)在面對(duì)一個(gè)不太熟悉的項(xiàng)目是尤為重要。如果建筑物結(jié)構(gòu)設(shè)計(jì)至少具有中等（或標(biāo)準(zhǔn)）的效益時(shí)，前面所提到的百分比就對(duì)建筑物總造價(jià)估算有著很大的幫助。例如，如果一座辦公樓總體造價(jià)500萬(wàn)美元，其中有25%時(shí)結(jié)構(gòu)造價(jià)的標(biāo)準(zhǔn)，那么這一工程結(jié)構(gòu)體系造價(jià)就不能超過(guò)125萬(wàn)美元。若設(shè)計(jì)很合理，比如時(shí)按上述的中等效益設(shè)計(jì)估算造價(jià)的80%時(shí)，那么就有25萬(wàn)美元，也就是5%的總體建筑費(fèi)用被省下來(lái)。如果這500萬(wàn)資金已經(jīng)到位，那么節(jié)省下的25萬(wàn)美元就可用于其他的經(jīng)濟(jì)開(kāi)支。上面所有闡述表明，結(jié)構(gòu)設(shè)計(jì)和建筑整體設(shè)計(jì)（機(jī)械和電器）的創(chuàng)造性結(jié)合的概念，將有助于減少單純的結(jié)構(gòu)造價(jià)，或在相同造價(jià)下提供更多的建筑費(fèi)用。這樣，設(shè)計(jì)成功的程度將取決于設(shè)計(jì)者的專業(yè)知識(shí)、靈活性以及設(shè)計(jì)者和承包人之間有洞察力的合作，上面討論僅僅是提供一種關(guān)于建筑總體造價(jià)的全面視圖，下面的部分將提供對(duì)建筑的結(jié)構(gòu)造價(jià)進(jìn)行估價(jià)的方法。有兩種可供選擇的方法將用來(lái)進(jìn)行結(jié)構(gòu)造價(jià)的近似估價(jià)：其一是根據(jù)單位平方英尺建筑面積，另一種則是根據(jù)所用的結(jié)構(gòu)材料體積進(jìn)行估價(jià)。參考上面所提到的有效設(shè)計(jì)的結(jié)構(gòu)造價(jià)標(biāo)準(zhǔn)，最后的結(jié)構(gòu)估價(jià)有助于對(duì)建筑的總體造價(jià)驚醒大概的了解。當(dāng)然，這樣得到的只是一個(gè)粗略的估價(jià)，但卻會(huì)使設(shè)計(jì)負(fù)責(zé)人員對(duì)實(shí)際設(shè)計(jì)中經(jīng)常要面對(duì)的經(jīng)濟(jì)問(wèn)題有所了解。至少，這些將有助于對(duì)可供選擇的結(jié)構(gòu)體系的相對(duì)成本效益進(jìn)行對(duì)比。3.平方英尺估算如前所述，在一個(gè)特定的時(shí)期和地區(qū)，是可以根據(jù)相似工程的平均造價(jià)，來(lái)經(jīng)驗(yàn)地確定準(zhǔn)平方英尺造價(jià)系數(shù)。設(shè)計(jì)者和承包人有效的利用材料和勞動(dòng)力的能力不同，會(huì)導(dǎo)致不同平均水平的經(jīng)濟(jì)效率設(shè)計(jì)的。對(duì)于“標(biāo)準(zhǔn)”的結(jié)構(gòu)體系而言，每平方英尺的造價(jià)為10~16美元，例如，典型的辦公樓平均水平在12~16美元之間，而住宅型建筑的范圍則是10~14美元。對(duì)以上兩種情況，下限適用于短跨低矮的建筑，而上限則是用于較大跨度及中等高度的建筑。如同典型的住宅性建筑，普通工業(yè)建筑結(jié)構(gòu)簡(jiǎn)單，通常每平方英尺的造價(jià)為10~14美元。盡管工業(yè)建筑的跨度很大，且荷載較重，但他