Construction cost index for plumbing works in office and commercial buildings

Updated: 14 January 2022

Next update: 14 February 2022

Change in total plumbing costs
Change in total plumbing costs
December 2020 - December 2021

About the statistics

The index measures the monthly cost development of plumbing installations in office and commercial buildings. It is used for contract escalation in construction contracts between plumbing companies and building contractors.

Labour cost is divided into two main components, which are calculated separately: wages and salaries for actual worked hours, and other labour costs. Other labour costs include wages and salaries for hours not worked and social security charges.

A Laspeyres price index is a price index where the weights remain fixed. A chained Laspeyres price index is an index linked by Laspeyres indices with different sets of weights.

Price: Actual sales prices to the construction industry. Price on the 15 th of each month exclusive VAT.

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Name: Construction cost index for plumbing works in office and commercial buildings

14 February 2022

Topic: Prices and price indices

National level only.


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Price observations from the wholesale dealers are stored on Excel-spreadsheet.

The CCI measures the changes in the prices of input factors to the construction process of plumbing works. CCI ignores gains in productivity and changes in profit margins.

The indices are published since 1999.

The CCI is used used for contract escaltion in construction contracts between plumbing companies and building contractors

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Some data are collected from the Consumer Price Index, Wage Statistics and Cost index for road goods transport.

Statistics Act Sections 2-2 and 2-3.

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Construction cost indices measures the price developments of material, labour, transport, plant and other types of input factors for plumbing works in office and commercial buildings, i.e. costs incurred by the carrying out the construction work. It is two different types of information to be collected about the input factors, the percentage of each component (weights) and the prices. The weights are compiled every tenth year through cost studies of plumbing works. The prices are measured monthly.

The material prices are collected from wholesale dealers.

The labour costs are based on Statistics Norway's quarterly wage statistics and a percentage of social security charges according to wages.

Transport costs indices compiled by Statistics Norway.

All the main suppliers of plumbing materials, provides about 325 price observations every month.

The material prices are collected by e-mail.

Reporting and record keeping burden

An outlet uses an average of 25 minutes every month to fill in the questionnaires.

The prices are put through tests, which identify observations with large price changes from the previous month. Prices are also checked when sorted by item and when items are aggregated into groups. Sub-indices and item-indices are checked against time-series that are published earlier and comparisons with other statistics.

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The construction cost index is calculated as Laspeyres Index.

The outlets might, for the sake of convenience, copy the previous month's prices instead of the correct prices when filling out the questionnaires. The most obvious cases of this kind are revealed in a manual check carried out when receiving the questionnaires.

When a product or service is no longer sold the outlets are instructed to find a replacement and mark it in the questionnaire. If they fail to do so, the difference in price between the old product and the replacement will incorrectly be registered as a price change of the old product.

The sample of eight main wholesale dealers covers 80 per cent of the turnover.

Sampling errors are not calculated.

Non-sampling errors

For some goods prices measurements are based on price lists, and changes in discounts given to building contractors are not taken into account.

Price effects due to changes in relative prices.

The price ratio between different goods and services has been changed over time.

Unsatisfactory handling of quality changes.

Statistics Norway has not initiated separate calculations of the impact of these measuring errors in the building cost indices.

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