Hellenic Statistical Authority (ELSTAT) 

Business Statistics Division (B3)

Manufacture – Construction Indices and Industrial Products Section (B33)

Pireos 46 & Eponiton Str., 18510 - Piraeus

The Cost Indices for the Construction of New Residential Buildings (CSTI - variable 320 of Regulation 1165/1998) consist of the monthly Materials Costs Index (CSTM - variable 321 of Regulation 1165/1998) and the quarterly Price Index of Labour Renumaration or Labour Costs Index (CSTL - variable 322 of Regulation 1165/1998).

The data are monthly or quarterly when they are collected and refer to Greece total and are presented as indices and rates of change. The indices are compiled on a quarterly basis and are released as follows:

   -  Indices with base year 2015=100.0

   -  Quarterly rates of change,

   -  Annual rates of change.

For the compilation of the indices the following classifications are used:

• Statistical classification of economic activities NACE Rev.2 of EU (pursuant to Regulation (EC) 1893/2006 of the European Parliament and of the Council).
• Classification of types in Construction – CC Classification.

Moreover, for the Material Costs Index, a national classification is followed, which includes 91 categories of materials, aggregated in 15 groups, whereas the Price Index of Construction Cost follows the national classification, which includes 24 works categories aggregated in 11 groups.

The indices cover Section F - Construction of NACE Rev.2 and specifically group 41.2, which concerns the construction of residential buildings.

Overall Costs Index for the Construction of New Residential Buildings (CSTI) (variable 320 of Regulation 1165/98). This index reflects the changes in the costs, incurred by the constructors for the construction of a standard residential building (block of flats) and it is calculated on the basis of the material prices and the labour remuneration paid by them. This index is compiled from the aggregation of two individual price indices: i) the Material Costs Index for the Construction of New Residential Buildings (CSTM) (variable 321 of Regulation 1165/98), which is a monthly input index reflecting changes in building material prices and ii) the Price Index of Labour Remuneration or Labour Costs Index (CSTL) (variable 322 of Regulation 1165/98), a quarterly input index which monitors the evolution of labour remuneration for the individual works performed for the raising of a new residential building construction.

Labour is a major factor in the construction of residential buildings and has a pivotal role in the overall construction costs.

The reporting units for the collection of prices are the construction enterprises and the contractors.

The reference population is the total of construction and construction contractors and new building construction contractors. The selection of sample enterprises took place in the biggest urb cities, based on their turnover and the ability to provide continuous pricing.

The geographical coverage refers to the whole of the country. only from the biggest cities of Greece according to the census 2011 results, as the: Greater Athens, Thessaloniki, Patras, Herakleion, Larisa and Volos.

From the 1^st quarter 2000 onwards, the time series for the Overall Costs Index for the Construction of New Residential Buildings, with base year 2015 (2015=100.0), is available on a quarterly basis (while time series for the Materials Costs Index, with base year 2015 (2015=100.0), is available on a monthly basis).

The base year is the year 2015 (2015=100.0). 

Indices, percentage changes (%).

The reference period is the quarter for the overall costs index (quarter for the labour costs index and month for the material costs index).

The legal framework concerning the organization and operation of ELSTAT is as follows:

The Legal Framework is detailed in the following link:

http://www.statistics.gr/en/legal-framework

EU legislation:

The legal basis for the STS indices is Council Regulation No 1165/98 of 19 May 1998 concerning short-term statistics (STS-R) as amended by the Regulation (EC) No 1158/2005 of the European Parliament and of the Council of 6 July 2005 concerning short-term statistics and by Regulation (EC) No 1893/2006 of the European Parliament and of the Council of 20 December 2006 establishing the statistical classification of economic activities NACE Rev.2.

The definitions of short-term statistics variables are laid down in Commission Regulation No 1503/2006 of September 2006 implementing and amending Council Regulation No 1165/98 of 19 May 1998 concerning short-term statistics.

The data of the Price Indices of Construction Cost of New Residential Buildings are transmitted to Eurostat, according to Council Regulation (EC) No 1165/1998 “concerning short-term statistics”, as amended by Regulation (EC) No 1158/2005 of the European Parliament and of the Council.

The issues concerning the observance of statistical confidentiality by the Hellenic Statistical Authority (ELSTAT) are arranged by articles 7, 8 and 9 of the Law 3832/2010 as in force, by Articles 8, 10 and 11(2) of the Regulation on Statistical Obligations of the agencies of the Hellenic Statistical System and by Articles 10 and 15 of the Regulation on the Operation and Administration of ELSTAT. More precisely, ELSTAT disseminates the statistics in compliance with the statistical principles of the European Statistics Code of Practice and in particular with the principle of statistical confidentiality.

http://www.statistics.gr/en/statistical-confidentiality

- ELSTAT protects and does not disseminate data it has obtained or it has access to, which enable the direct or indirect identification of the statistical units that have provided them by the disclosure of individual information directly received for statistical purposes or indirectly supplied from administrative or other sources. ELSTAT takes all appropriate preventive measures so as to render impossible the identification of individual statistical units by technical or other means that might reasonably be used by a third party. Statistical data that could potentially enable the identification of the statistical unit are disseminated by ELSTAT if and only if:

a) these data have been treated, as it is specifically set out in the Regulation on Statistical Obligations of the agencies of the Hellenic Statistical System (ELSS), in such a way that their dissemination does not prejudice statistical confidentiality or
b) the statistical unit has given its consent, without any reservations, for the disclosure of data.

- The confidential data that are transmitted by ELSS agencies to ELSTAT are used exclusively for statistical purposes and the only persons who have the right to have access to these data are the personnel engaged in this task and appointed by an act of the President of ELSTAT.

- ELSTAT may grant researchers conducting statistical analyses for scientific purposes access to data that enable the indirect identification of the statistical units concerned. The access is granted provided the following conditions are satisfied:

a) an appropriate request together with a detailed research proposal in conformity with current scientific standards have been submitted;
b) the research proposal indicates in sufficient detail the set of data to be accessed, the methods of analyzing them, and the time needed for the research;
c) a contract specifying the conditions for access, the obligations of the researchers, the measures for respecting the confidentiality of statistical data and the sanctions in case of breach of these obligations has been signed by the individual researcher, by his/her institution, or by the organization commissioning the research, as the case may be, and by ELSTAT.

- Issues referring to the observance of statistical confidentiality are examined by the Statistical Confidentiality Committee (SCC) operating in ELSTAT. The responsibilities of this Committee are to make recommendations to the President of ELSTAT on:
· the level of detail at which statistical data can be disseminated, so as the identification, either directly or indirectly, of the surveyed statistical unit is not possible;
· the anonymization criteria for the microdata provided to users;
· the granting to researchers access to confidential data for scientific purposes.

- The staff of ELSTAT, under any employment status, as well as the temporary survey workers who are employed for the collection of statistical data in statistical surveys conducted by ELSTAT, who acquire access by any means to confidential data, are bound by the principle of confidentiality and must use these data exclusively for the statistical purposes of ELSTAT. After the termination of their term of office, they are not allowed to use these data for any purpose.

- Violation of data confidentiality and/or statistical confidentiality by any civil servant or employee of ELSTAT constitutes the disciplinary offence of violation of duty and may be punished with the penalty of final dismissal.

ELSTAT, by its decision, may impose a penalty amounting from ten thousand (10,000) up to two hundred thousand (200,000) euros to anyone who violates the confidentiality of data and/or statistical confidentiality. The penalty is always imposed after the hearing of the defense of the person liable for the breach, depending on the gravity and the repercussions of the violation. Any relapse constitutes an aggravating factor for the assessment of the administrative sanction.

At the end of September of each year ESLTAT publishes a Press Releases Calendar where figure the exact release dates of all the data for next year.

The press releases calendar is disseminated to the media and it is available to users for free. The release calendar is also posted on the web page of ELSTAT “Press Releases” / “Release Calendar”: http://www.statistics.gr/en/calendar

In compliance with the Community legal framework and the European Statistics Code of Practice, ELSTAT disseminates national statistics on ELSTAT’s website respecting professional independence and in an objective, professional and transparent manner in which all users are treated equitably.

In this content, data are released simultaneously to all interested parties and users through the press release on the CSTI , which is released on the official website of ELSTAT (https://www.statistics.gr/en/home) according to the press releases calendar. This press release is also made available by fax or e-mail to all interested parties. In addition, data are transmitted to Eurostat on a predefined date, concomitantly with their national publication.

Neither users nor the government have access to the data prior to their publication.

The Overall Construction Costs Index of New Residential Buildings is disseminated on a quarterly basis. The Material Costs Index for the Construction of New Residential Buildings is disseminated on a monthly basis.

Every quarter, approximately 25 days after the end of the reference quarter, at 12:00 pm, a press release is released concerning the newly compiled indices in Greek and in English. The press release is sent, free-of-charge, and mostly by email to the press and to other interested parties. The press release is also available on the website of ELSTAT website (https://www.statistics.gr/en/home/) at:

http://www.statistics.gr/en/statistics/-/publication/DKT63/-

In addition, The Material Costs Index for the Construction of New Residential Buildings is released on a monthly basis through the corresponding Press Release, approximately 25 days after the end of the reference month. The press release is also available on the website of ELSTAT website at: http://www.statistics.gr/en/statistics/-/publication/DKT60/-

The index is published in the publication of ELSTAT “Greece in Figures” (http://www.statistics.gr/en/greece-in-figures), as well as in specialized publications of Eurostat.

There are no available data on the Construction Costs Indices (Material Costs Index and Labour Costs Index) of New Residential Buildings on the on-line database of ELSTAT.

Microdata are made available to users after their submitting a request to the:

Division of Statistical Information and Publications

46, Peiraios and Eponiton Str.,

18510 Piraeus

Tel: +30 213 135 2022

Fax: +30 213 135 2312

e-mail: data.dissem@statistics.gr

For confidentiality reasons access to microdata is granted to users only under strict conditions and by always adhering to the relevant procedure.

Apart from the dissemination of the data to Eurostat, users can be given data or further analysis, usually by fax or e-mail after submitting a request, describing the requested data, to the Section of Statistical Dissemination, at the following e-mail addresses: data.dissem@statistics.gr and data.supply@statistics.gr.

Users can also submit their requests electronically, through the portal at:

https://www.statistics.gr/en/statistical-data-request

More links for data dissemination:

http://dlib.statistics.gr/portal/page/portal/ESYE/

http://www.statistics.gr/en/statistics/-/publication/DKT63/-

http://www.statistics.gr/en/statistics/-/publication/DKT60/-

http://ec.europa.eu/eurostat/web/short-term-business-statistics/

The methodology for the compilation of the index is laid down by ELSTAT, taking into account international practices and, in particular, Eurostat’s recommendations, guidelines and standards.

The methodological issue that includes a set of guidelines for the preparation of short-term statistics is available:

Methodology of short-term business statistics - Interpretation and Guidelines

Moreover, the information note on the compilation of the Work Categories and for the Construction Costs Index of New Residential Buildings in Greece, which includes the methodology that is implemented for the compilation of the indices is available at the following link:

http://www.statistics.gr/en/statistics/-/publication/DKT63/-

A concise user-oriented quality report is available on the website of ELSTAT at: http://www.statistics.gr/en/statistics/-/publication/DKT63/-

Quality checks and validation of data are carried out during the whole process of the compilation of the index: from the data collection stage to the final compilation of the index.

First of all, well-trained and experienced staff is utilized for all the stages of the compilation of the indices, that is, for data collection including communication with the enterprises, initial checks, data entry and final checks, which are conducted after the calculation of the index. This way, the personnel have a comprehensive and longitudinal image of the enterprises under their responsibilities.

Data are validated either before or after data entry by means of logical checks. During data processing the data are checked in order to identify and correct any errors. When an error is identified, data are further investigated, in cooperation with the enterprises in order to confirm that it is an error or it is just an unusual price. At the same time, data are checked for completeness, accuracy and consistency of the correlating variables.

The index is calculated by means of specialised software, through computation routines, thus eliminating any errors to the final results. Nevertheless, even during this stage, consistency checks are carried out on the final results, mainly by means of comparing the rates of change of the individual indices.

Moreover, in order to ensure the quality of data, all the procedures that are described in the circulars on the Quality Policy of ELSTAT are followed: http://www.statistics.gr/en/policies

Generally, the Price Indices of Work Categories and the Construction Costs Index of New Residential Buildings are considered as highly reliable indices. Theses indices are being compiled in Greece since 1981, thus the staff has acquired a lot of experience in their compilation. In addition, concepts and definitions of variables, as well as relevant methodology for the compilation of the Indices follow European and international standards and guidelines.

The Construction Costs Index of New Residential Buildings covers national needs, as well as needs of European and other users. Among the main national users are: the government, public services, the Bank of Greece, other banks, the Hellenic Federation of Enterprises (SEV), the Foundation for Economic and Industrial Research (IOVE), technical or other Chambers, etc. At international level:  Eurostat, IMF, UN, etc.

The compiled indices cover the wide range of users’ needs: as concerns domestic market, the indices are used as a tool providing useful information on monitoring the prices in the construction sector, thus helping the government in drawing economic policy and enterprises or other agencies in decision making concerning their taking up several initiatives. At European level, there is the need for fully comparable statistics in order to draw the European economic policy.

The Manufacture – Construction Indices and Industrial Products Section monitors on regular basis users’ needs in order to satisfy them. More generally, there is a smooth cooperation resulting to the best possible response to user’s requests, and comments made by users are positive.

In addition, ELSTAT conducts:

a. A users’ satisfaction survey.

Every six month, ELSTAT conducts a user’s satisfaction survey. The results of this survey are published in the “Library’s Newsletter” (in Greek and English), a publication which is issued by the Library of ELSTAT and by the Section of Statistical Information Dissemination, on the basis of information deriving from the User Questionnaire. This publication present semi-annual data on the number of users in combination with other variables, such as the degree of satisfaction of users’ requests, the kind of the requested data and the modes of statistical dissemination. These data are presented in the form of tables, absolutes values and percentage points.

b. A User Conference

In accordance with its Annual Statistical Work Programme, ELSTAT, from 2010 onwards, has been conducting a User Conference, on a yearly basis with the participation of representatives of the private and public sector, academics, researchers and research institutes. These conferences give ELSTAT the opportunity to gather comments and interventions made by the users of statistics on issues such as the dissemination of statistical information, access of users to statistics and any omissions in the statistical output. The User Conferences help ELSTAT to draw useful conclusions on how the statistical output and the services provided can be improved so as to meet user’s growing needs. These conclusions are incorporated in the annual statistical work programmes of ELSTAT.

More information on the results of the user’s satisfaction surveys and on the user conferences are available at:

http://www.statistics.gr/en/user-satisfaction-survey

https://www.statistics.gr/en/user-conference

The compilation of the indices and the data provided are fully in line with the relevant EU Regulations.

The accuracy of the indices is generally considered to be high. ELSTAT does not calculate sampling errors for these indices because the purposive sampling technique is applied, instead of the random sampling technique. As regards non-sampling errors, they mostly refer to measurement or non-response errors. The efforts which are made mostly focus on identifying and eliminating, to the extent possible, these errors, through the revision of data.

In compliance with Council Regulation (EC) 1165/1998 concerning “short-tem statistics”, short-terms indices should be revised every five years and more specifically in years ending in 0 or 5. In this framework, the Construction Costs Index for New residential Buildings is fully revised every five years with the change of the base year and the adoption of the new weights. 

Sampling error is not estimated for the indices because of the purposive sampling technique are applied. About 280 commercial or industrial enterprises, supplying materials to constructors or construction enterprises are used as the reporting units for monthly material prices collection. For electricity (mainly the construction electricity), prices are collected from the Public Power Corporation, while for water, data are provided by water supplies companies. As a source of the labor price index, 323 technical construction companies and contractors are being investigated. The selection of sample enterprises was made in the largest urban centers, based on their turnover and the ability to provide continuous pricing.

The indices cover Greece-total and prices are collected in the biggest urban centres (Athens and surroundings, Thessaloniki, Patra, Irakleio, Larisa and Volos).

The Material Costs Index calculates the price changes of 91 categories of materials aggregated in 15 groups, by recording price data of 1,512 varieties of that kind of materials.

The labour remuneration index records the changes in the prices of 24 job categories, aggregated into 11 groups, and prices are collected from 420 reporting units.

Unit non – response

In case of non-response, the surveyed enterprise is contacted by telephone or is sent a reminder by fax or e-mail or even a statistical interviewer pays a visit to the enterprise in order to collect the required information. Total response rate is generally considered to be high, amounting to 99%.

Item non - response

There are not any errors related to the inconsistent implementation of definitions. If some products or variations of products cease to be representative or change their characteristics on the basis of which they are defined, new items or similar items are used to replace them. In these cases, their calculation, for the base year, is based on the use of the indices of the group in which they belong. Missing values are treated by estimating them by “repeating the last prices” during the period of non-response.

Coverage error

No coverage errors are observed in the Business Register of ELSTAT, on the basis of which the survey on the compilation of the index was designed.

Over-coverage – rate

No over-coverage errors (e.g., closed enterprises, enterprises out of the scope of the survey, etc.) are observed in the Business Register of ELSTAT, on the basis of which the survey on the compilation of   the index was designed.

Common units – proportion

The index is compiled on the basis of a common sample of enterprises for each month, which is renewed with the change of the base year. Therefore, the percentage of common enterprises of the sample among the months is 100%.

Measurement error

Measurements errors occur during data collection.  They are identified by means of quality checks and are duly corrected.

Processing error

After data collection a series of processes takes place before the compilation of the index, such as weighting of enterprises, calculations by implementing mathematic formulae, tabulation of results, etc. There are some processing errors, such as errors on account of erroneous information provided by the surveyed enterprises. These errors are usually easy to be identified by means of checks and cross-checks of data with the corresponding data of the previous years after contacting by phone the enterprise. There are no processing errors as regards the use of the relevant software application.

Model assumption error

No model is used for the compilation of the index.

The indices are published approximately 25 days after the end of the reference quarter. 

The indices are published in accordance with the pre-announced release calendar. Any delays in the release of data are due exclusively to extraordinary events.

The compilation of the index is based on relevant EU legislation and on basic methodology on short-term statistics used throughout EU Member States, thus the survey produces fully comparable results, taking always into consideration specific conditions in each country, which may require minor deviations from methodology.

The available full time series of the revised indices (2015=100.0) consists of the converted indices for the period 2000-2018 and of the calculated indices using the new weighting scheme after the change of the base year from 1^st quarter 2019 onwards (for Material Costs Index from January 2019 onwards).

Therefore, the time series of the indices with base year 2015=100.0, which is available from 1^st quarter 2000 onwards, is considered fully comparable over time.

Checks are carried out regularly on the basis of data from other surveys. More specifically, comparisons are made with the sub-indices of the Consumer Price Index and with the Production Index in Construction.

Coherence – sub annual and annual statistics

The common sample of enterprises used for the index ensures the accurate representation of the evolution of the indices during several time periods.

Coherence – National Accounts

The indices are used by the National Accounts Division for the compilation of their estimations and for converting current prices to constant prices.

The calculated indices are internally coherent. Higher-level aggregates derive from detailed indices according to well-defined procedures.

On the basis of the results of the survey on cost and burden that was conducted by ELSTAT for the year 2018: a) the estimated cost, as regards the personnel of ELSTAT involved in the compilation of the indices, amounted to 648 hours and b) as regards the surveyed enterprises, the average annual burden, estimated in hours needed for the provision of the relevant information, is 0.5 hours per enterprises, or 168 hours for all the surveyed enterprises.

Moreover, for CSTM the results are: a) the estimated cost, as regards the personnel of ELSTAT involved in the compilation of the CSTM, amounted to 1,710 hours and b) as regards the surveyed enterprises, the average annual burden, estimated in hours needed for the provision of the relevant information, is 1.8 hours per enterprises, or 514 hours for all the surveyed enterprises.

The quarterly indices are published 25 days (t+25) after the end of each reference quarter. Data are final when first released.

The data are revised, in accordance with the Revision Policy of ELSTAT, which is available at the following link: http://www.statistics.gr/en/policies

Whenever the data are revised, the same revision policy is applied to data released nationally ant to those transmitted to Eurostat, in order to ensure coherence.

According to the requirements of the Council Regulation (EEC) No 1165/98 concerning short-term statistics, short-term indices are revised every five (5) years, particularly on calendar years ending with a 0 or a 5. In this framework, major revisions of the Prices Indices of Construction Costs Index for New residential Buildings (CSTI) take place every five years, with the change of the base year and implementation of the new weighting scheme.

In order to compile the Construction Costs Index for New residential Buildings a survey is carried out.

The observation units for the collection of prices are the construction enterprises and the contractors.

The indices cover Greece-total and price collection takes place in the biggest urban centres (Athens and surroundings, Thessaloniki, Patra, Irakleio, Larisa and Volos).

For the Material Costs Index, 280 commercial or industrial enterprises, supplying materials to constructors or construction enterprises are used as the reporting units. For electricity, prices are collected from the Public Power Corporation, while as regards water, data are provided by water supply companies. The index calculates the price changes in 91 categories of materials aggregated in 15 groups, by recording price data of 1,512 varieties of that kind of materials.

The prices of these materials are those which are actually paid by the construction enterprises for materials supplied at the site and do not include VAT or other taxes. Prices are collected on a monthly basis and usually refer to the middle period of the reference month.

The labour remuneration index records the changes in the prices of 24 job categories, aggregated into 11 groups, and prices are collected from 420 reporting units.

The prices on labour remuneration of the overall costs index in construction of new residential buildings are the rates actually paid by construction enterprises to the groups of technicians that they employ. The remuneration is usually agreed by the construction enterprise and by the specialized technicians group and the technicians are paid at piecework rates. These are the rates that are quarterly collected and refer to the contracts signed during the reference quarter.

Data for materials are collected on a monthly basis and for labour remuneration on a quarterly basis.

Data are collected by specialized employees–price collectors and for this purpose specially designed questionnaires are used for this purpose, adapted to each enterprise. The price data for materials provided by each enterprise are pre-printed in the questionnaires and the prices charged for these materials are requested, during the reference month. In addition, the questionnaires are sent in electronic format to the competent Regional Statistics Services which are responsible to collect the relevant data.

The prices are collected by means of the following ways:

-with personal visits of price collectors to the enterprises

-via telephone contacts

-via fax

-via e-mail.

Non-response is treated by telephone contacts, faxes, e-mails and personal visits of interviewers to the enterprises.

Data are validated by means of logical checks. Data processing encompasses investigation of data in order to identify and duly correct any errors. Special emphasis is put on the errors that have significant impact on the results. After identifying errors, further investigation takes place in cooperation with the enterprise in order to confirm that it is an error or just an unusual price. Moreover, completeness checks are carried out in order to confirm that the values are within given ranges and that values for related variables are coherent. The data processing and data validation takes place either during or after data entry.

The data are compared with the data of the previous quarters and inconsistencies or major deviations lead to more thorough investigation.

For the calculation of all the general indices, overall cost, material index and labour remuneration, the variation of the Laspeyres formula was used, as follows:

where:

: is the general price index for the current period (quarter, year t)

: is the individual price index of material varieties or labour renumeration or the overall cost i in the current period t and

  : is the weight of material varieties or labour renumeration or the overall cost i,

x_i: the value of the work category, the labour remuneration or the overall cost i in 2015, i= 1,2,...,n, where n is the number of material varieties or labour renumeration or the overall cost.

The individual indices of the material varieties or labour renumeration categories i is the simple arithmetic mean of the relevant prices of this materials varieties or labour renumeration prices from all the reporting units, i.e.:

where :

   : is the count of materials varieties or labour renumeration prices i from all the reporting units

: is the price j of the reporting unit of materials varieties or labour renumeration i for the current period t

: is the average annual price j of the reporting unit of materials varieties or labour renumeration i in the base year 2015.

Backdated calculations (rescaled) of the monthly, quarterly and annual individual indices for the period: 1st quarter of 2000 - 4th quarter of 2018 (January 2000 - December 2018, for Material Costs Index) were adjusted calculated using the annual index of every material, labour category or overall cost index in the year 2015, according to the following type:

where:

 : is the individual material, labour category or overall cost index i in the current period (month, quarter, year) t with 2015 as base year,

 : is the individual material, labour category or overall cost index i in the current period (month, quarter, year) t with 2010 as base year and

 : is the individual mean annual index of the material, labour category or overall cost index i in 2015, with 2010 as base year.

Imputation – rate

No imputed values are used to substitute price collection in sample enterprises. Missing values are treated by estimating them by “repeating the last prices” during the period of non-response.

No adjustment for data correction is used.

The data are not seasonally adjusted.

None