Construction cost index

Results and their publication

As with the old index, since January 2006 the new index for construction of residential buildings (base year 2005 = 100) has been published as an overall index, subdivided into the Wages and Others cost groups for building contractors’ activities. As of January 2006, the new index for road and bridge construction has – as was the case with the old index – been published as an overall index, further subdivided into the separate cost groups of Wages and Others. In addition, the index is subdivided into partial indices according to activity groups in accordance with the relevant specifications, and bitumen is identified according to its country of origin.

Initial preliminary results are published 15 days after the end of the month under review, and revised figures are published after 45 days. Exact publication dates for the first and second half of the year can be found in Statistics Austria’s publication calendar (available in German only). Current figures are published monthly in the STATAS table bank (available in German only), the ISIS database (available in German only), in press releases and on the Eurostat website.

Definition 

The construction cost index for construction of residential buildings and for road and bridge construction underwent a revision (new baskets of goods and new weighting schemes) in 2005 in order to take into account changes in construction technology and methods as well as new environmental standards and technical specifications for construction in the index calculations. As of January 2006, the construction cost indices for construction of residential buildings and for road and bridge construction are calculated and published taking the 2005 average = 100 as the base (for more information, see “Documentation” (available in German only)).

The construction cost indices observe the development of costs that construction companies incur when performing construction activities as a result of changes to fundamental costs (materials and labour). The construction cost indices are used both as a basis for the evaluation of contracts with escalation clauses and for price alignment in construction contracts, and are available for construction of residential buildings, road construction and bridge construction (for more information, see “Documentation” (available in German only)).

Calculation

For both structural and civil engineering, the Laspeyres index formula (fixed basket of goods, fixed weighting) is used for the calculations. Using the index number method, each individual price for a commodity (cost factor) is shown (at current price/base price) by means of an index number (= index number at survey unit level) that can be compared with the corresponding base price (base: 2005 average = 100). These index numbers give an unweighted average index number for each cost factor, with the geometric mean applied instead of the arithmetic mean since the base year 2005. This reflects the general trend in price statistics and international recommendations for this method of calculation.

The index numbers are largely obtained from secondary sources (such as the wholesale price index) or calculated using available price information (from the producer price index, for example, or on the basis of figures collected from primary sources) and aggregated according to the individual weightings for each cost factor. This provides the indices for the individual group indices and the overall index. The weighting is based on the base year 2004, and the cost basis is based on the 2005 average.

Breakdown of the results

As with the old index, since January 2006 the new index for construction of residential buildings (base year 2005 = 100) has been published as an overall index, subdivided into the Wages and Others cost groups for building contractors’ activities. As of January 2006, the new index for road and bridge construction has –  as was the case with the old index – been published as an overall index, further subdivided into the separate cost groups of Wages and Others. What is new, however, is that partial indices are calculated and published for each activity group in accordance with the current specifications for transport infrastructure construction (LB-SW 04) or the technical specifications for bridge construction (RVS 7B) instead of the Others cost group being subdivided into 3 (for roads) or 10 (for bridge construction) cost groups. There are 18 partial indices for road construction and 16 partial indices for bridge construction; as a result, price conversions in construction contracts can in future be listed separately for each activity group. The partial indices are then weighted together to form an overall index for roads or bridges. In addition, for road construction, bitumen will continue to be identified and subdivided according to its country of origin. Preliminary figures will be published 15 days after the end of the month under review, and final figures will be available after 75 days (t+75 is required for the final figures because the final results for producer price information, which is now included in the construction cost index for civil engineering, are not available earlier).

In addition, the summary reports 2.12 – Construction cost index for construction of residential buildings and 2.14 – Construction cost index for road and bridge construction are published monthly and are available to download free of charge from “Further information” and “Publications” (available in German only).

More detailed explanations of the methodology can be found in “Further information” and “Documentation” (available in German only).