【正文】 都應給予充分的重視。后者將會因為時公開支費用的降低，是承包商快速贏利。模板通常是現(xiàn)場澆制混凝土構件的決定性因素，因此，為得到每立方碼150美元的價格，需要采用最簡單的體系方可，例如需要很少的模板加工量并可多次使用平板。而每平方米低于20磅的設計，則需要很強的創(chuàng)造力以及建筑物設計和結構設計上完美的結合，其可稱得上是一個真正的成就。以重量計的建筑鋼材的現(xiàn)場價格。體積量度估價，是通過制定結構系統(tǒng)中需要的以磅或噸記得鋼材、立方體的鋼筋或預應力混凝土的現(xiàn)場價格來實現(xiàn)的。無論如何，長跨度體系都有其特殊性，它可能較多，也可能較少的影響總體建筑造價時，對于特殊的建筑物，其結構造價將隨著設計的不同而明顯地改變 。工業(yè)建筑中較大的荷載也無形中提高了建筑物的結構造價。因此，其結構造價在總體造價中的比重接近也普通建筑物。變化的限度取決于體系的復雜程度、跨度超長的程度、特殊的荷載級地震條件等。如同典型的住宅性建筑，普通工業(yè)建筑結構簡單，通常每平方英尺的造價為10~14美元。如前所述，在一個特定的時期和地區(qū)，是可以根據(jù)相似工程的平均造價，來經(jīng)驗地確定準平方英尺造價系數(shù)。有兩種可供選擇的方法將用來進行結構造價的近似估價：其一是根據(jù)單位平方英尺建筑面積，另一種則是根據(jù)所用的結構材料體積進行估價。若設計很合理，比如時按上述的中等效益設計估算造價的80%時，那么就有25萬美元，也就是5%的總體建筑費用被省下來。相反，即使對于最為普通的建筑設計，如果僅僅靠設計手冊，是很難取得經(jīng)濟效益的。創(chuàng)造性設計受限往往是因為設計者或承包商在經(jīng)驗、想象力際交流方面的匱乏。對于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，其結構造價在總體造價中將占較高的百分比（約30%~35%），而服務費用約占30%~40%。對于一些中等高度（5~10層）得多層辦公樓或住宅樓，其結構造價在總體造價中所占的比例，大約維持在25%這一中間值；而對于一些低矮且跨據(jù)短的商業(yè)用房和住宅，大約3~4層高且跨度為20~30英尺以及簡單的豎向要求，其結構造價將占總造價15%~20%。一般而言，結構造價所占的百分比可低至工程總造價的10%~15%，這是因為更多的錢被用到那些非結構費用上了。顯然，上面講到的百分比平均數(shù)有些粗略，但是它足以說明總體造價的組成情況了。第二種節(jié)約開支的途徑，則是設計人員在設計過程中綜合考慮服務設施和結構體系，盡力提出一個能夠解決房屋設計和施工難題的總建筑方案。但現(xiàn)在這種狀況正在迅速改變，因為高利率以及資金的缺乏，現(xiàn)在大多業(yè)主更傾向于節(jié)約型設計?！盎痉赵O施費”組成了第三類工程費用，主要是指機械供給、電器設備以及其他一些服務體系等費用。不過上面這些因素都不在本文的討論范圍之內(nèi)，文章將重點介紹工程造價。特別是今天，人們應該逐漸認識到，高雅和經(jīng)濟其實是一個可以統(tǒng)一的概念。如果事先清楚結構設計及施工組織方案與實現(xiàn)他們的造價之間的關系，那么創(chuàng)造性是同樣可以實現(xiàn)的。 and garagetype structures span,50 to 60 ft, carrying relatively light(50～75 psf) loads(., similar to those for apartment and office structures).where these spans are doubled, the structural costs can be expected to rise about 20 to 30 percent.To increased loading in the case of industrial buildings offers another insight into the dependency of cost estimates on “usual” standards. If the loading in an industrial building were to be increased to 500psf(., two or three times), the additional structural cost would be on the order of another 20 to 30 percent.The reference in the above cases is for floor systems. For roofs using efficient orthotropic (flat) systems, contemporary limits for economical design appear to be on the order of 150 ft, whether of steel or prestressed concrete. Although space frames are often used for steel or prestressed concrete. Although spaceframes are often used for steel spans over 150 ft the fabrication costs begin to raise considerably.At any rate, it should be recognized that very longspan subsystems are special cases and can in themselves have a great or small effect on is added, structural costs for special buildings can vary greatly from design to design. The more special the form, themore that design knowledge and creativity, as well as construction skill, will determine the potential for achieving cost efficiency.4. VolumeBased EstimatesWhen more accuracy is desired, estimates of costs can be based on the volume of materials used to do a job. At first glance it might seem that the architect would be ill equipped to estimate the volume of material required in construction with any accuracy, and much less speed. But it is possible, with a moderate learning effort, to achieve some capability for making such estimates.Volumebased estimates are given by assigning inplace value to the pounds or tons of steel, or the cubic yards of reinforced or prestressed concrete required to build a structural system. For such a preliminary estimate, one does not need to itemize detailed costs. For example, inplace concrete costs include the cost of forming, falsework, reinforcing steel, labor, and overhead. Steel includes fabrication and erection of ponents.Costs of structural steel as measured by weight range from ﹩ to ﹩ per pound in place for building construction. For lowrise buildings, one can use stock wideflange structural members that require minimum fabrication, and the cost could be as bow as ﹩ per pound. More plicated systems requiring much cutting and welding(such as a plicated steel truss or spaceframe design) can go to ﹩ per pound and beyond. For standard tall building designs (say, exceeding 20 stories),there would typically be about 20 to 30 pounds of steel/psf, which one should wish not to exceed. A design calling for under 20 psf would require a great deal of ingenuity and the careful integration of structural and architectural ponents and would be a real acplishment.Concrete costs are volumetric and should range from an inplace low of ﹩150 per cu yd for very simple reinforced concrete work to ﹩300 per cu yd for expensive small quantity precast and prestressed work. This large range is due to the fact that the contributing variables are more plicated, depending upon the shape of the precise ponents, the erection pr