Reference metadata describe statistical concepts and methodologies used for the collection and generation of data. They provide information on data quality and, since they are strongly content-oriented, assist users in interpreting the data. Reference metadata, unlike structural metadata, can be decoupled from the data.
Turkish Statistical Institute (TURKSTAT) Necatibey Cad. No:114 Çankaya/ANKARA
1.6. Contact email address
Confidential because of GDPR
1.7. Contact phone number
Confidential because of GDPR
1.8. Contact fax number
Confidential because of GDPR
2.1. Metadata last certified
1 October 2025
2.2. Metadata last posted
1 October 2025
2.3. Metadata last update
1 October 2025
3.1. Data description
Construction Cost Index (CCI): Price index that measures of the changes in construction costs in terms of labor and materials by months
3.2. Classification system
The Statistical Classification of Products by Activity (CPA Version 2.1) is used for CCI.
3.3. Coverage - sector
F. Construction
41 Buildings
41.00.1 Residential building
41.00.2 Non residential buildings
42 Civil Engineering
42.1 Roads and railways
42.2 Utility projects
42.9 Other civil engireering projects
3.4. Statistical concepts and definitions
Substance weights used in the calculation of the construction cost index for the 2015 base year are calculated by using the input amounts determined by analyzing the approximate cost and final account files of the construction projects obtained from various public institutions and organizations and the unit prices of the year 2015.
In the weighting of building types, building registration data is used for buildings and National Account data is used for civil engineering.
3.5. Statistical unit
Observation unit: Price indices and administrative data
Reporting unit: Index and changes of monthly and yearly
3.6. Statistical population
In order to determine the material and workmanship and their weights, 77 construction projects were analyzed to represent construction types, resulting in about 2,300 products and weights. The cost index is calculated for each type of structure resulting from matching these products with the related price index in the lowest detail.
In the calculation of the series with 2015 = 100 base year and current weight structure, Domestic Producer Price Index, Consumer Price Index, Service Producer Price Index and Social Security Institution administrative data are used in the bottom detail.
3.7. Reference area
Turkey
3.8. Coverage - Time
1991=100 based Bulding Construction Cost Index was first used in November, 1992.
2005=100 based Bulding Construction Cost Index was first used in April, 2007.
2015=100 based Construction Cost Index was first released in March,2018.
3.9. Base period
At national level, the construction cost index is published with base year 2015, Eurostat publishes indices with base year 2021 From March 2024 onwards.
Indices and percentage changes.
Reference period is monthly.
6.1. Institutional Mandate - legal acts and other agreements
At European Level:
European Business Statistics (EBS) Regulation (EU) 2019/2152 on 27 November 2019, followed by the Commission Implementing Regulation 2020/1197
At National Level:
The compilation and dissemination of the data are governed by the Turkish Statistical Law No. 5429 of November 10, 2005. The purpose of this law is to determine basic principles and standards concerning the production and organisation of official statistics; and to regulate the formation, duties, and authorities of the Turkish Statistical Institute (TurkStat) which is to compile and assess data and information, produce, publish, and disseminate statistics on the areas that country needs, and to ensure coordination among institutions and organizations that are involved in the statistics process prescribed in the Official Statistics Programme (Article 1).
The Official Statistics Programme establishes the framework for official statistics that shall be produced on subjects required at national and international level. Censuses and surveys are carried out within the framework of this Programme (Article 3).
6.2. Institutional Mandate - data sharing
Data are transmitted to Eurostat only. (for residential buildings construction cost index)
7.1. Confidentiality - policy
All statistics collected and published by TURKSTAT are governed by the Turkish Statistical Law no. 5429, of 10 November 2005. Under the terms of the Statistical Law:
TURKSTAT has the independence to determine the methodology and release dates of statistics for which it is responsible.
Data are collected only for statistical purposes and confidentiality is assured.
The confidentiality of individual responses is guaranteed.
The TURKSTAT logo is used on all statistics published under the law.
The public dissemination of economic statistics is required.
7.2. Confidentiality - data treatment
Weights of prices of items are confidential.
8.1. Release calendar
The data release calendar for statistical outputs is prepared on an annual basis and it is publicly announced on the National Data Release Calendar section of the website.
8.2. Release calendar access
Publication dates and times of the press releases published by the Turkish Statistical Institute are available at National Data Release Calendar.
8.3. Release policy - user access
The principles, standards and procedures regarding the publication and dissemination of statistics produced by Turkish Statistical Institute are determined by the Publication and Dissemination Board. In order to ensure that statistics are delivered to users in accordance with the principles of confidentiality and equal access, and in an accurate, reliable, consistent, timely, and transparent way, the publishing dates of the press releases are determined within the framework of the Directive on the Procedures and Principles Regarding the Working Calendars of the Presidency of the Turkish Statistical Institute and announced to the public via the institutional website at the beginning of each year.
European Statistics Code of Practice (CoP) are the quality principles and standards established by the European Union. CoP; It consists of 3 main sections: institutional environment, statistical processes and statistical outputs. There are 16 quality principles and 84 quality indicators under these principles. TurkStat carries out its activities in accordance with the CoP's quality principles and indicators. The CoP is available on the Eurostat's website.
Institutional Quality Reports
Institutional quality reports are prepared for annual studies. The relevant quality report can be accessed under the Metadata tab on the Statistics Data Portal.
ISO 9001:2015 Quality Management Documentation
Quality-related documents were created within the scope of the ISO 9001:2015 Quality Management standard. Procedures, guides, instructions, plans, lists, and forms are included in the quality management system along with the standard coding system. There is a "Document Control Procedure" for the creation and updating of the documents. In addition, all studies are detailed on the basis of the articles of the standard in the "Quality Handbook", prepared within the scope of the ISO 9001:2015 Quality Management standard.
11.1. Quality assurance
TurkStat Quality Policy
TurkStat is committed to implementing a quality policy based on the European Statistics Code of Practice (ES-CoP), the European Statistical System Quality Assurance Framework (ESS-QAF), and other internationally recognized best practices determined by the European Statistical Office (Eurostat). In this context, TurkStat strictly adheres to and implements quality standards in statistical production processes by adopting the principle of continuous improvement and excellence in accordance with the ISO 9001:2015 Quality Management System Standard.
TurkStat Quality Policy is avaliable on the TurkStat website.
Quality Assurance Framework
The Quality Assurance Framework of the European Statistical System (ESS QAF) is a supporting document that aims to assist in the implementation of the European Statistics Code of Practice (CoP). It identifies possible activities, methods and tools that can provide guidance and evidence for the implementation of the CoP's indicators. TurkStat has determined its own quality assurance framework according to the QAF and shares it with all users on the TurkStat website. In line with the principles of the CoP, TurkStat quality assurance framework includes the studies, tools and legal regulations.
ISO 9001:2015 Quality Management System
TurkStat is certified by the “ISO 9001:2015 Quality Management System” standard. TurkStat implements a holistic quality management system by fulfilling all the necessary requirements of the standard.
11.2. Quality management - assessment
Quality Monitoring and Assessment Tool (QMAT).
TurkStat aims to increase the quality of statistics by evaluating the compliance of official statistics produced with quality principles and standards based on European Statistics Practice Principles (Code of Practice-CoP). As a result of the quality assessment carried out with QMAT, areas open to improvement are determined and improvement action plans are created. The actions scheduled in the improvement action plan are regularly monitored to ensure continuous improvement in the quality of official statistics.
12.1. Relevance - User Needs
There are sections on the website of our institution for users who want to access both general and detailed information. After selecting the topic interested in from the "Subcategories" part of the "Statistics" section and clicking on the "Search" button, "Press Release", "Statistical Tables", "Databases", "Reports" and "Metadata" contents can be reached.
Data at international and regional level can be accessed through the "Regional Statistics", "Provincial Indicators", "International Selected Indicators", and "Turkstat Library" applications in the "E-Services" section.
Data requests which cannot be replied are compiled regularly and data production process are addressed in the light of this information.
12.2. Relevance - User Satisfaction
Statistics produced by the Turkish Statistical Institute are presented to users through various channels, and a number of studies are carried out to increase service quality and meet user needs. The user satisfaction survey, which is one of these studies, is conducted through the corporate website in order to determine the profile, needs, and expectations of the users. The results of the survey are reported annually.
The index is broken down into three groups of costs: Labour, Materials, Total
The index is released in 8 division in accordance with CPA 2.1:
F. Construction
41 Buildings
41.00.1 Residential building
41.00.2 Non residential buildings
42 Civil Engineering
42.1 Roads and railways
42.2 Utility projects
42.9 Other civil engireering projects
Eurostat's requirements in term of time series are fulfilled. Moreover, CCI actually meets the Turkish users needs of information
13.1. Accuracy - overall
Received CCI (Construction Cost Index) results are analyzed, looking for errors, which may affect the final results. Outliers are determined by using SAS programme, and some computings are made by using excel and SAS together. Price indices and administrative data provide quality checked data for CCI.
13.2. Sampling error
CCI are derived from D-PPI, CPI and administrative data. The size of statistical error is not calculated.
13.3. Non-sampling error
The non-sampling error is not calculated.
14.1. Timeliness
Publication is released 51-53 days after the end of the reference month.
14.2. Punctuality
The news releases are published according to the announced release calendar.
15.1. Comparability - geographical
Turkey CCI is produced only on the whole country level.
15.2. Comparability - over time
TurkStat calculates CCI since 2018. Time series of BCCI breaks are he following:
1991-2006; base 1991
2005-2017; base 2005
2015- ; base 2015
Eurostat publishes indices with base year 2021 From March 2024 onwards.
15.3. Coherence - cross domain
Coherence is insured for Labour cost since data derived by the administrative data from Social Security Institution; materials costs are collected by PPI and CPI.
15.4. Coherence - internal
CCI is internaly coherent. Lower level price indices are aggregated to the higher level indices and the total CCI.
There is no responder burden. In calculating process, current price indices and administrative data are used.
17.1. Data revision - policy
Data are not subject to revision.
17.2. Data revision - practice
Not avaliable
18.1. Source data
Type of source Different types of sources are used. Material prices are mainly colleçted from Domestic Producer Price Index, Service Producer Price Index and Consumer Price Index. Labour costs are derived from administrative source: Social Security Institution
Frame on which the source is based Weights for types of construction and items used in compilation of 2015 based CCI were calculated evaluating bill of quantities obtained from various public institutions and organizations(eg.Housing Development Administration, The General Directorate of Highways) with 2015 unit prices.
Criteria for stratification Not applicable
Threshold values and percentages Not available
Frequency of updating the sample Sample is updated every 5 years.
18.2. Frequency of data collection
Data are collected monthly.
18.3. Data collection
Questionnaires are not used in the survey. In the calculation of the series with 2015 = 100 base year, Domestic Producer Price Index, Service Producer Price Index, Consumer Price Index and Social Security Institution data are used.
18.4. Data validation
The experts of the CCI carries out the first verification and editing as well as validation of the data using the SAS programme. Data are compared to the data of previous periods. Reasons of changes in the prices of cost items are analysed. Before computing the index, data are quality-checked by observing both levels and rates of change.
18.5. Data compilation
The CCI is computed by applying Laspeyres formula with fixed base year (2015=100). It is not a chained index.
18.6. Adjustment
Not available
Not available.
Construction Cost Index (CCI): Price index that measures of the changes in construction costs in terms of labor and materials by months
1 October 2025
Substance weights used in the calculation of the construction cost index for the 2015 base year are calculated by using the input amounts determined by analyzing the approximate cost and final account files of the construction projects obtained from various public institutions and organizations and the unit prices of the year 2015.
In the weighting of building types, building registration data is used for buildings and National Account data is used for civil engineering.
Observation unit: Price indices and administrative data
Reporting unit: Index and changes of monthly and yearly
In order to determine the material and workmanship and their weights, 77 construction projects were analyzed to represent construction types, resulting in about 2,300 products and weights. The cost index is calculated for each type of structure resulting from matching these products with the related price index in the lowest detail.
In the calculation of the series with 2015 = 100 base year and current weight structure, Domestic Producer Price Index, Consumer Price Index, Service Producer Price Index and Social Security Institution administrative data are used in the bottom detail.
Turkey
Reference period is monthly.
Received CCI (Construction Cost Index) results are analyzed, looking for errors, which may affect the final results. Outliers are determined by using SAS programme, and some computings are made by using excel and SAS together. Price indices and administrative data provide quality checked data for CCI.
Indices and percentage changes.
The CCI is computed by applying Laspeyres formula with fixed base year (2015=100). It is not a chained index.
Type of source Different types of sources are used. Material prices are mainly colleçted from Domestic Producer Price Index, Service Producer Price Index and Consumer Price Index. Labour costs are derived from administrative source: Social Security Institution
Frame on which the source is based Weights for types of construction and items used in compilation of 2015 based CCI were calculated evaluating bill of quantities obtained from various public institutions and organizations(eg.Housing Development Administration, The General Directorate of Highways) with 2015 unit prices.
Criteria for stratification Not applicable
Threshold values and percentages Not available
Frequency of updating the sample Sample is updated every 5 years.
Monthly.
Publication is released 51-53 days after the end of the reference month.
Turkey CCI is produced only on the whole country level.
TurkStat calculates CCI since 2018. Time series of BCCI breaks are he following:
1991-2006; base 1991
2005-2017; base 2005
2015- ; base 2015
Eurostat publishes indices with base year 2021 From March 2024 onwards.
