Dokumentation og international benchmarking af bygge - Danmarks ...

DifficultiesThe difficult part of this method is to select representative standard componentsand to determine the weighting structure so that they reflect constructiontechniques and the composition of buildings. In order to keepthis index representative the current construction types and underlyingcomponents might be replaced or redefined periodically. Furthermore, itis difficult to compare the construction projects over time, since they areall individually built. Numerous quality and quantity corrections shouldbe undertaken in order to eliminate all other factors but “pure” pricechanges.An additional fact is that productivity and profit margins of the componentscannot be measured directly, because they are indirectly included inthe reported price. The prices are collected for selected and well-definedconstruction components. These are the prices that enterprise has agreedwith client. Within the agreed price the builders cover their costs (materials,wages, etc.) and make the profit. The way productivity changes arereflected in price is considered to be the result of internal company’s policy.It could lead to lower expenditures and increase the profit margins orthe company could decide to reduce the offer prices to improve the competitiveness.Hence, the overall profit cannot be measured.The profit margin and productivity related to the work process of combiningthe building components to the finished building is not measuredwith the method. In this manner, the components cost method is an inputprice index, with "large" input components (e.g. complete walls instead ofnails and bricks).Finally, in countries where the reporting of prices for the compilation ofthese indices is not compulsory, it could be difficult to motivate the respondentsto answer the questionnaires.Collected pricesIn principle, the prices collected should be purchasers' prices, i.e. pricesactually paid in the markets for the defined construction types. The followingpoints must be taken into account during price collection:• The unit prices used in the major components must cover the producer'scosts properly for each elementary component (such as materials,labour, hire of equipment, sub-contractor's fees etc.).• The unit prices must be adjusted to include the profit margin of thecontractor, general expenses (including the appropriate share of mainoffice overheads) and for all preliminary expenses connected to theconstruction type. They must be taken into account if the contractorusually is obliged to pay them, either by law or by common practice.Preliminaries, overheads and profit margin are usually estimated inpractice.• The unit prices shall not include architects’ or engineers’ fees, sincethese are not part of the activities in the construction industry.• The unit prices shall not be adjusted for the expenditure incurred forthe purchase of land (cost of the land itself and related financial andnotary costs).71