Dokumentation og international benchmarking af bygge - Danmarks ...

espective component in the previous quarter.Matched model methodHedonic methodUsing the matched model method it is also not straight forward when itcomes to ensure the same model being priced in two subsequent periods.Actually, for construction projects the possibility of longitudinally followingidentical models does not really exist. The building projects startedin a reference period is not the same as those started in the last period andtheir location and characteristics are likely to differ from period to period.For construction projects, it is very difficult to obtain a measure of pureprice changes, not disturbed by the changes in quality, and the methoddoes not offer any method to correcting for quality changes apart fromsimple calculation corrections.The use of a hedonic regression model makes it possible to adjust for differencesin quality between the building projects started in the previousperiod and buildings project started in the reference period. The regressionmodel can express the price per square meter as a linear function ofvariables indicating location and characteristics of the buildings. Thetricky task is to decide which variables to include in the model to achievethis nice characteristic in practice and not just in theory. The question is tosome extend what range of r-squares is to be accepted and still being ableto claim, that it in fact can be look on as a hedonic method.Practical considerationsData sourcesData collection andpotential respondentsDifferent options where to collect the data from have been evaluated.One of the possibilities is to select the respondents from the enterprisesclassified under NACE 45 construction in the Business Register (BR) ofStatistics Denmark that concerns mainly construction enterprises and relatedservice providers (e.g. joiners, plumbers, tiling and flooring, electricians).BBR can provide information on buildings location, utility floor space andinformation on the owner, while the building contractors/investors canprovide information about prices and quality characteristics that may influencethe price.Another possibility is obtaining the information on granted building permits,which can be provided from the municipalities, or alternatively obtaininginformation on granted loans from different Housing banks‘kreditforeninger’.Component cost methodThis method requires only information on the prices of the constructionelements being reported from respondents. The quality of the componentis defined by the statistical office. The respondents can be selected basedon the BR.103