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.
Unit SED (Index of production in construction - IPC)
1.3. Contact name
Confidential because of GDPR
1.4. Contact person function
Confidential because of GDPR
1.5. Contact mail address
Economic Statistics Directorate - Short Term Statistics Division
Via Tuscolana, 1788
00173 Rome
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
13 June 2025
2.2. Metadata last posted
13 June 2025
2.3. Metadata last update
13 June 2025
3.1. Data description
The monthly index of Production in Construction (IPC) is one of the economic indicators required by Regulation (EU) 2019/2152, to monitor and evaluate developments in the construction sector. The related Implementing Regulation (EU) 2020/1197 calls for the provision of the IPC for the entire construction sector (section F of NACE Rev.2) starting from the reference period January 2005. Moreover, from January 2021 onwards, it requires the provision of IPC broken down by NACE Rev.2 Divisions: Construction of buildings (F41), Civil Engineering (F42) and Specialized Construction Activities (F43).
The monthly Index of Production in Construction (IPC) measures all construction activities, including the production of new manufactured products and the maintenance of existing products (section F of the NACE Rev. 2 economic activity classification). The index is constructed on a fixed basis and uses 2021 as the reference year.
The compilation index is also provided for by the current Italian National Statistical Programme.
Starting from the press release of 27 March 2024, the estimation method of the IPC has been completely revised (see next paragraph) according to the EBS methodological manual for compiling the monthly index of production in construction – 2021 edition.
3.2. Classification system
NACE Rev. 2.
3.3. Coverage - sector
Section F of NACE Rev.2. Breakdown: Divisions F41 (Construction of buildings), F42 (Civil Engineering) and F43 (Specialized Construction Activities).
Hours worked: in principle, enterprises with no employees or more.
3.4. Statistical concepts and definitions
List and definition of variables:
the monthly Index of Production in Construction – Section F of NACE Rev.2
the monthly Index of Production in Construction - Divisions F41 of NACE Rev.2
the monthly Index of Production in Construction - Divisions F42 of NACE Rev.2
the monthly Index of Production in Construction - Divisions F43 of NACE Rev.2
The monthly Index of Production in Construction (IPC) measures all construction activities, including the production of new manufactured products and the maintenance of existing products (section F of the NACE Rev. 2 economic activity classification). The index is constructed on a fixed basis and uses 2021 as the reference year. It is compiled from input data (hours worked provided by the Building Workers Welfare Funds (BWWF), monthly productivity coefficient calculated using the annual National Accounting data and electronic invoicing data provided by Revenue Agency) applying an indirect method.
The variables directly surveyed for IPC are those related to labour input: hours worked, number of manual workers and number of enterprises. They are administrative data but collected by Istat through a monthly survey. Input data are combined to estimate the output of the construction sector.
3.5. Statistical unit
Reporting unit (s):
Hours worked: Register Building Workers Welfare Funds (BWWF). After collecting information on hours worked and number of manual workers of enterprises that subscribed the specific contract for the construction sector, these organizations (BWWF) transmit data to Istat.
Observation unit(s):
Construction enterprises
3.6. Statistical population
Theoretical statistical population is represented by the total of the enterprises of the construction sector.
3.7. Reference area
The area covered by the IPC is the whole national territory.
3.8. Coverage - Time
The IPC index data of section F are available since 1995.
The IPC indices data of Divisions F41, F42 and F43 are available since 2021.
3.9. Base period
The base year is 2021.
Index.
Month.
6.1. Institutional Mandate - legal acts and other agreements
Legal basis:
National level:
Monthly survey on Building Workers Welfare Funds is one of the compulsory surveys administered as part of the National Statistical Programme (current edition: NSP 2023-2025) approved with a Decree of the President of the Republic, published in Ordinary Supplement No. 39 of the Official Journal - General series – No. 268 of 15 November 2024.
Commission Regulation No.1503/2006 defining variables and frequency of data compilation, repealing new orders received for building construction and new orders received for civil engineering.
Commission Regulation No. 472/2008 introducing the new base year 2005 and the statistical classification of economic activities, NACE Rev. 2, into short-term statistics
Obligation on units to provide data:
Hours worked: Enterprises that have signed the construction sector contract are required to provide information on hours worked to BWWF, collected by ISTAT through a compulsory monthly survey, provided for NSP.
Industrial turnover: There is a legal requirement for enterprises involved in the "Monthly Survey on Industrial Turnover" (refer to metadata on "STS Industrial Turnover Index").
Planned changes in legal basis, obligation to respond and frame used:
In 2016, ISTAT revised the "Monthly Survey on BWWF," making it both mandatory and a census survey. Since the 2015 rebasing, data from the total 98 BWWFs have been utilized to compile the Index of Production in Construction (IPC).
6.2. Institutional Mandate - data sharing
No other transmissions to international organisations except Eurostat.
7.1. Confidentiality - policy
Confidentiality provisions are explicitly stated in the ISTAT President’s letter sent every year by email to all BWWF along with references to different acts on statistics. Several national legal acts guarantee the confidentiality of data requested for statistical purposes. According to art. 9, paragraph 1 of the Legislative Decree n. 322 of 1989, personal data can only be disseminated in aggregate form, in order to make it impossible to identify individuals. The Personal Data Protection Code (introduced by the Legislative Decree no. 196 of 30 June 2003) and the Legislative Decree no. 101 of 10 August 2018 (compliance Decree to Regulation UE no. 679/2016 - General Data Protection Regulation) provide special rules concerning the processing of personal data for statistical purposes within the National Statistical System (Sistan). Further, in order to make statistical secrecy and protection of personal data effective, Istat is currently taking appropriate organisational, logistical, methodological and statistical measures in accordance with internationally established standards. Links to different legal acts on statistics are listed on Sistan’s website - National Statistical System - Sistan - Normativa della statistica ufficiale.
7.2. Confidentiality - data treatment
Survey elementary data are treated as confidential. Aggregated data are disseminated in Istat website..
Aggregated data on hours worked provided by BWWF are processed and stored in a database, but not released.
Data transmitted to Eurostat encompass 4 variables, yet only 1 of them is disseminated at the national level and it remains embargoed until national dissemination. The remaining 3 variables are transmitted with confidential flags. The Index of production in construction for the first transmission to Eurostat (t+45) is transmitted with confidential too, because it occurs before the national dissemination. After the national dissemination, data become free for Eurostat.
8.1. Release calendar
In December of each year, ISTAT publishes a release calendar, detailing the exact release dates for the upcoming year. This calendar is distributed to the press and is freely available to all interested parties.
Data are released simultaneously to all interested parties by issuing the press release “Production in the construction sector” on ISTAT’s website. There is no pre-release access. Data are also sent to Eurostat according to required standards by EDAMIS4 using SDMX format. Every month, data are transmitted to Eurostat no later than 45 days after the end of the reference month. Eurostat receives embargoed all 4 variables until national press release and 3 out of four variables are with confidentiality flag; they are not disseminated nationally, because they are not considered significant for the national press release.
Monthly.
10.1. Dissemination format - News release
"Production in the construction sector” is a monthly press release with graphs and tables that ease the data analysis; a short text explains recent evolution for the phenomenon. It includes information on methodological aspects through a “Methodological note”, attached to the press release.
The press release (ltalian version and English short version) is disseminated on IPC website Istat.
Data series are disseminated in seasonally adjusted form (with month on previous month percentage changes), in the calendar-adjusted form and in non-adjusted form (with month on same month a year ago percentage changes).
The IPC index data of section F are available since 1995, instead the IPC indices data of Divisions F41, F42 and F43 are available since 2021.
10.2. Dissemination format - Publications
Data are made available to the public through yearly publication “Annuario Statistico Italiano” (ASI) -Italian Statistical Yearbook, which includes a graph of the monthly production indicator in the construction sector (seasonally adjusted data).
10.3. Dissemination format - online database
The data can be accessed in the IstatData database, under the theme “Industry and Construction” and the sub-theme “Production/Index of production in construction”.
Data series are disseminated (since 1995) in seasonally adjusted form (with month on previous month percentage changes), in the calendar-adjusted form and in non-adjusted form (with month on same month a year ago percentage changes).
The IstatData online database is open and free to use. It organises statistics by theme in a two-level hierarchical structure. Data are presented in aggregate form within multidimensional tables. Users can create custom tables and graphs by adjusting variables, reference periods, and the layout of rows and columns. The system allows for searches by keyword and theme.
Comprehensive standard metadata is available to assist users in retrieving and understanding the statistics. For more detailed information, please refer to the User Guide.
A wide range of standard metadata facilitates the retrieval and understanding of statistics by users.
10.4. Dissemination format - microdata access
Before data dissemination, validated microdata are stored in an ISTAT database called ARMIDA (Archive of Validated Microdata). This repository also collects additional useful information, such as metadata and classifications, to ensure the correct interpretation of the data. ARMIDA was established with the primary objective of preserving and documenting the data produced by all internal ISTAT surveys. It also supports the goal of disseminating data. The microdata archived in ARMIDA serve various dissemination channels, including: the “Access Protocol of Microdata of ARMIDA” for internal users, Adele’s Laboratory and authorities within the Sistan network, an external environment for research files, standard files. Additionally, microdata are stored in an internal Oracle database.
10.5. Dissemination format - other
Data are sent to Eurostat to be used in European aggregates. F index sent to Eurostat is embargoed and it becomes available for national dissemination only after they have been published by ISTAT. F41, F42 and F43 indices are transmitted to Eurostat confidentially.
10.6. Documentation on methodology
A detailed description of the survey methodology and characteristics is provided in the technical explanatory note, which is regularly updated and attached to the monthly press release. Starting from January 2024 provisional data, the estimation method of the IPC has been completely revised according to the “EBS methodological manual for compiling the monthly index of production in construction – 2021 edition”. Methodology and sources of information for the new index calculation are described in "Nota informativa" attached to the press release of 27th March 2024.
10.7. Quality management - documentation
Metainformation on statistical production processes and secondary processes is contained in the Information System on Quality (SIQual). SIQual includes metadata on process content, operational characteristics (process phases and operations), and quality measures. These quality measures encompass activities related to error prevention, monitoring, and evaluation (quality actions) as well as documentation on process and product quality. SIQual (SIQual/IPC) is accessible on ISTAT's website. Additional details about the procedures applied for quality management and quality assessment can be found in the document "Quality Guidelines for Statistical Processes" (August 2016).
11.1. Quality assurance
ISTAT's quality policy aligns with the European Statistics Code of Practice, initially adopted in 2005 and revised in 2011 and 2017, as well as with Eurostat's Quality Definition and the recommendations of the LEG on Quality. In accordance with these principles, Italy has adopted the Italian Code of Official Statistics to enhance the quality of statistics produced by the Italian National Statistical System. Essential points of Istat quality policy are: process and product quality, documentation, respect for respondents, strengthening of statistical literacy and users’ orientation. For more details: Istat website - quality_commitment.
Quality assurance for this survey, in the framework of the quality policy of Istat, is based on the implementation of various activities, such as
Prevention and monitoring of non-respondent, initiatives to foster survey participation and follow-ups of non-respondent units;
Submission of on-line questionnaires to some variable compatibility checks; checking of few fields during data entry;
Coherence control with previous data of the same survey;
Elaboration of a set of standard quality indicators.
11.2. Quality management - assessment
The overall quality assessment can be considered satisfactory, as there is a compliance between the production process and Istat quality guidelines. Index of production in construction is relevant with regard to users’ information needs, it is accurate and easily accessible and supported by metadata allowing for a perfect understanding of the data, they allows comparisons over time and respect the timing. A set of standard quality indicators is regularly analysed and these are available on SIQual (Information System on Quality), presented with graphs and tables for easy analysis. For more information, please refer to: Siqual - Information System on Quality
12.1. Relevance - User Needs
Users mainly manage these data for studying evolution and planning policies at national or local level.
Main users of Index of production in costruction are:
Institutions: government departments, ECB, national central bank, international organisations, etc.
Social actors: employers' organisations, trade unions, lobby groups (national building contractors' association), etc.
Media
Researchers & students
Enterprises/businesses
Internal users
Eurostat.
12.2. Relevance - User Satisfaction
Not available.
12.3. Completeness
Eurostat's requirements for time series data are fully met.
13.1. Accuracy - overall
All measures to reduce errors have been implemented, ensuring the overall accuracy of the index is good. Additionally, there is an average lag of 9.5 months between the provisional and final releases, during which the indicators typically exhibit a consistent trend.
13.2. Sampling error
An assessment of the sampling error for IPC is not available, as IPC estimate is based on an indirect method that uses hours worked as the sole productive input. Data on labour input used for the IPC compilation are obtained through a statistical census survey.
13.3. Non-sampling error
Non-sampling errors are mitigated through a series of proactive measures. During the collection phase, strategies such as email reminders, deadline notices, and telephone contacts are employed to minimize late transmissions and enhance response rates. Since March 2022, the implementation of an online procedure has aimed to further increase response rates and streamline data validation through compatibility checks on key variables. Additional actions include thorough checking procedures for individual fields during data entry and automated error checks post-entry. At the moment (reference year: 2024), the response rate is on average 94.2% for the t+75 estimate. For the preliminary IPC estimate, BWWF data used represent almost 76.4% of the responding units (74-90 out of 106). A higher number (78-92) of the responding units is used for the t+75 estimate, covering almost the 94.3% of the 106 potential responding units.
14.1. Timeliness
ISTAT provides a provisional estimate of the monthly value of the IPC, typically 45 days past the end of the reference month and transmits it confidentially to Eurostat, which uses these indices in the calculation of the European aggregates. Subsequently, these estimates undergo revision 75 days after the reference period. Provisional estimates are then released at national level approximately 50 days past the end of the reference month. Initially, the data is provisional at the time of first release, with subsequent revisions leading to finalization coinciding with the annual review which typically occurs in March of the year following the reference period when information on hours worked is completed.
14.2. Punctuality
Both European and national releases are punctual, adhering to the designated timelines for dissemination.
15.1. Comparability - geographical
Data dissemination at the national level adheres to European definitions outlined in CR 1503/2006, ensuring consistency across the entire national territory in terms of definitions and methodologies. The data used to compile the index essentially covers the entire national territory, as the 106 welfare funds involved in the BWWF survey are distributed across all Italian geographical regions, even if for some of them the response rate is slightly lower than the national average. Furthermore, the quality (completeness) of the data transmitted appears to be less satisfactory for some regions, whose BWWFs collect data on businesses with a delay.
15.2. Comparability - over time
With the publication of the provisional index for January 2024, the new series of non-adjusted data, corrected for calendar effects and seasonally adjusted are released based on the 2021 reference base.
The F series starts from the year 1995:
- for the years prior to 2021, the non-adjusted series were reconstructed through a shift operation of the data previously published based on 2015, in order to keep the trend variations of the original series unchanged;
- starting from the year 2021, the indices have been recalculated with the new estimation method based only on labor input.
The F41, F42 and F43 series start from the year 2021.
15.3. Coherence - cross domain
Comparisons with Building permit indices highlight consistent trends, with any discrepancies typically attributable to the weight of these indices, which constitute approximately 40% of the total construction sector data. VA estimates from quarterly national accounts are based on monthly IPC, therefore good consistency is ensured between NA and STS data on construction production data.
15.4. Coherence - internal
Insofar as raw data are considered, IPC is consistent with its sub-aggregates. However, inconsistencies can emerge when working days adjusted data and seasonally adjusted data are considered, as seasonal adjustment is carried out indirectly.
The cost estimate is compiled in terms of total number of hours worked (THW). It is equal to the product of three terms: (total) Annual Working Days (AWD), (total) Hours Worked per Day (HWD), Number of Persons involved in the Survey (NPS).
AWD
HWD
NPS
Cost estimate (THW)
220
7.12
0,65
1,018
The burden estimate is compiled in terms of total number ofminutes (TNM) taken to fill in the questionnaire.
Respondents (BWWF) spend about 15 minutes on the questionnaire. Enterprises face no burden as they provide data for administrative reasons.
Existing information supports intermediate consumption and capital indices, covering both STS and national requirements.
Type of Respondent
Burden estimate (TNM)
Respondent (to fill)
About 15 min.
17.1. Data revision - policy
The IPC value undergoes revisions, not only because of the base update, but also in order to reflect changes in input measures: hours worked, productivity coefficients and distribution quotas. Preliminary estimates for each month are typically issued around 45 days after the reference period. The first revision occurs in the month following the first release (75 days after the reference period), to include new data on hours worked. A second revision typically takes place in March of the following year, integrating both definitive hours worked data (which complete their annual revision cycle) and new estimates provided by National Accounting used for both monthly productivity calculations and distribution quotas. In relation to the distribution quotas, the update is subordinated to both the revision policy of the National Accounts data and the availability of the administrative electronic invoicing data provided by Revenue Agency. Annual revisions continue until National Accounting releases definitive data, about three years later. Monthly seasonally adjusted series are estimated each month to incorporate the latest responses and update seasonal factors. Consequently, with new data releases, seasonally adjusted values for previous months are also revised. Seasonal adjustment models undergo periodic revision, with a revision calendar prepared for internal staff only. Transparency of disseminated data is ensured, with major changes in methodology or other survey features promptly communicated through methodological notes attached to data releases. While errors are rare, if they occur, corrections are promptly disseminated to both Eurostat and the Istat website to inform users. Vintage data are stored in an internal database, with the same revision policy applied to data released nationally and transmitted to Eurostat
17.2. Data revision - practice
Data revision comprises these steps:
- the first revision occurs 30 days after the initial release, considering new data on hours worked received after the first estimate;
- a second revision takes place in March of the following year (t+1) after the initial estimate release, coinciding with the availability of new estimates provided by National Accounting
- index will be revised until the input data are considered definitive: that is, annual reviews will be carried out in March and may concern up to three years backwards.
The press release "Production in construction " includes a table titled " Production in construction, months on previous months and on same months a year ago percentage changes," detailing differences from previously disseminated data. Additionally, a methodological note provides further information on the revision policy, criteria, and periodicity. Various revision metrics are compiled for these variables, including Mean Revision (MR), Main Absolute Revision (MAR), Relative Mean Absolute Revision (RMAR%), and Max Absolute Revision (MaxAR). These metrics are calculated for month-on-month percentage changes compared to the same month a year ago, using unadjusted data for years 2022, 2023, 2024 and the reference base is 2021=100
Therefore data was provided only from 2024, as data is not comparable for previous periods due to the change in methodology.
These adjustments should be taken into consideration when interpreting the data and analysing the indicators
18.1. Source data
Starting from provisional data of January 2024, the estimation method of the IPC has been completely revised according to the EBS methodological manual for compiling the monthly index of production in construction – 2021 edition. The new methodology for calculating the IPC applies an indirect method and it uses as calculation input:
hours worked provided by the Building Workers Welfare Funds (BWWF) in the reference month;
monthly productivity coefficient, calculated using the annual National Accounting data (value added and hours worked in the construction sector);
distribution quotas calculated using the annual National Accounting data and the administrative electronic invoicing data provided by Revenue Agency. These quotas are used to divide the production of Nace Rev.2 Section F and obtain the production of the F41, F42 and F43 Divisions of Nace Rev.2
Although hours worked represent administrative information, data on labour input used for the IPC compilation are obtained through a statistical survey. Since 2016, the survey conducted on Building Workers Welfare Funds (BWWF) has become a census and since 2024 the BWWF have increased from 98 to 106. The trend and the rate of change of hours worked are always aligned, confirming the reliability of this index in describing the evolution of the sector output.
Through the census survey based on the 106 BWWF in Italy, Istat gathers information monthly on hours worked, on the number of workers and the number of businesses to which hours are referred. Collected data are checked for consistency accuracy.
18.2. Frequency of data collection
Monthly.
18.3. Data collection
Data collection media:
Data are collected by web site.
Questionnaires used to collect hours worked in the survey BWWF:
The monthly questionnaire is filled in online by BWWF. Data collection is facilitated through the website GINO, where respondents are required to log in to access the web questionnaire. The data have to be provided by BWWF within the first twelve days of the second month following the reference month. To mitigate late transmissions and enhance response rates, various measures are implemented, including email reminders, deadline notices and telephone contacts.
As regards the output (IPC), data can be compared with other statistical domains information.
Data validation is conducted through a multi-level approach, encompassing three types of rules:
Validation Level 0: This involves checks on the format and file structure to ensure data integrity and adherence to predetermined specifications.
Validation Level 1: Intra-dataset checks are performed at both the record and cell levels. These checks verify the consistency and accuracy of data within the dataset, identifying any anomalies or discrepancies. Outliers are detected and investigated and responding units (BWWF) are contacted again when necessary.
Validation Level 2: Revision checks and time series checks are carried out to ensure coherence with previous data from the same survey. This involves verifying the consistency of current data with historical trends and identifying any unusual deviations. Other general checks are made on the plausibility of hours worked growth rates in comparison with the trend of the number of employees (workers) and the number of enterprises they are referred to.
18.5. Data compilation
For each reference month, the estimation method uses information on hours worked from the BWWF, which are bodies responsible for managing various contractual terms at a territorial level. They collect data on the hours actually worked by workers and apprentices in the construction sector.
Through a census survey based on the 106 BWWF in Italy, Istat gathers information monthly on hours worked, on the number of workers and the number of businesses to which hours are referred. Collected data are checked for consistency accuracy. Additionally, comparisons with other Istat surveys have shown that data from the BWWF sufficiently approximate the trend of the labour input of the sector.
The provisional data on hours worked sent by the BWWF are then revalued applying coefficients, calculated on the basis on the deviation observed in the series between provisional and final data. These coefficients are calculated with regard to the geographical division of each BWWF. In general, the variance related to distribution j, for the month m of the year t, calculated for the transmission interval i, is defined by:
where:
The transmission interval i=1,2,3,… refers to the number of months following the reference period for which the data are transmitted; for example, i=1 means that the transmission of data occurs approximately 1 month after the end of the reference month, i=2 means that the transmission of data occurs approximately 2 month after the end of the reference month, and so on.
The revaluation coefficient of the hours of the geographical division j, for the month m of the year t, is calculated as the average of the deviations of the same month in the previous 3 (k) years:
where:
This procedure produces five different revaluation coefficients and five total hours, one for each geographical division.
Subsequently, the total number of hours of each geographical division is multiplied by its expansion coefficient, generating five partial totals of hours, which are then added together to provide the value of the revalued total hours. In general, indicating ∆_(j,m,t)^i as the revaluation coefficient for the month m of the year t, calculated for the geographical division j for the transmission interval i of the data and h_(j,m,t)^ , as the hours worked in the same period and related to the same geographical division j (with j=5), the estimate of the total hours revalued for the generic month m of the year t is given by
The total thus obtained (3) is then adjusted with a monthly productivity coefficient, calculated using the annual National Accounting data (value added and hours worked in the construction sector). Denoting π_(m,t) as the productivity coefficient for the month m in the year t, a proxy of the total value added of production in the construction sector will be expressed by the following relationship:
That means that an estimate of the overall value added in volume for the month m of the year t is derived from the product of the sum of the partial totals of the revalued hours worked of the geographical divisions and the monthly productivity coefficient (4). The overall volume of production thus obtained, represents a proxy for the value added of production in construction (section F). Then, the equation (4) is estimated for the same month of the previous year as well, but in this case, the value of the total hours of the month m of the previous year, H_(m,t-1)^ , will not be a revalued data, as by year t-1, the hours have completed the data revision cycle. The corresponding equation for the same month of the previous year will be:
where:
Finally, the official index for section F is calculated using the chain-linking method, applying the trend change calculated on the value added to the respective index of the same month of the previous year.
where:
18.6. Adjustment
The released data are presented in three forms: unadjusted, seasonally adjusted, and calendar adjusted.
Seasonal effects are corrected using the TRAMO-SEATS procedure, specifically Version 4 Linux Revision 942. All 4 series (F, F41, F42 and F43) are transmitted to Eurostat in a seasonally adjusted form.
With the addition of new monthly information, parameters are re-estimated each month, and seasonally adjusted series are revised from January 1995. The statistical models used for seasonal adjustments are periodically reviewed and updated to ensure a good fit with the time series. A Reg-Arima approach is employed for seasonal adjustment.
The adjustment process involves the manual correction of outliers, such as additive outliers, temporary changes, level shifts, and seasonal outliers, during the revision of seasonal adjustment models. The filter length is automatically determined based on diagnostics on residuals and critical values for outlier detection. Each series in the dataset follows a log-additive decomposition model and is directly adjusted
A multiplicative seasonal adjustment breakdown is adopted. Calendar adjustment is performed by using Italy national calendar which also considers national holidays.
The adjustment process involves the use of a single regressor that summarizes the number of working days and those connected to midweek holidays; a regressor to capture the effects of leap years, as well as the presence of seven additive outliers and one 'temporary change' type.
The monthly index of Production in Construction (IPC) is one of the economic indicators required by Regulation (EU) 2019/2152, to monitor and evaluate developments in the construction sector. The related Implementing Regulation (EU) 2020/1197 calls for the provision of the IPC for the entire construction sector (section F of NACE Rev.2) starting from the reference period January 2005. Moreover, from January 2021 onwards, it requires the provision of IPC broken down by NACE Rev.2 Divisions: Construction of buildings (F41), Civil Engineering (F42) and Specialized Construction Activities (F43).
The monthly Index of Production in Construction (IPC) measures all construction activities, including the production of new manufactured products and the maintenance of existing products (section F of the NACE Rev. 2 economic activity classification). The index is constructed on a fixed basis and uses 2021 as the reference year.
The compilation index is also provided for by the current Italian National Statistical Programme.
Starting from the press release of 27 March 2024, the estimation method of the IPC has been completely revised (see next paragraph) according to the EBS methodological manual for compiling the monthly index of production in construction – 2021 edition.
13 June 2025
List and definition of variables:
the monthly Index of Production in Construction – Section F of NACE Rev.2
the monthly Index of Production in Construction - Divisions F41 of NACE Rev.2
the monthly Index of Production in Construction - Divisions F42 of NACE Rev.2
the monthly Index of Production in Construction - Divisions F43 of NACE Rev.2
The monthly Index of Production in Construction (IPC) measures all construction activities, including the production of new manufactured products and the maintenance of existing products (section F of the NACE Rev. 2 economic activity classification). The index is constructed on a fixed basis and uses 2021 as the reference year. It is compiled from input data (hours worked provided by the Building Workers Welfare Funds (BWWF), monthly productivity coefficient calculated using the annual National Accounting data and electronic invoicing data provided by Revenue Agency) applying an indirect method.
The variables directly surveyed for IPC are those related to labour input: hours worked, number of manual workers and number of enterprises. They are administrative data but collected by Istat through a monthly survey. Input data are combined to estimate the output of the construction sector.
Reporting unit (s):
Hours worked: Register Building Workers Welfare Funds (BWWF). After collecting information on hours worked and number of manual workers of enterprises that subscribed the specific contract for the construction sector, these organizations (BWWF) transmit data to Istat.
Observation unit(s):
Construction enterprises
Theoretical statistical population is represented by the total of the enterprises of the construction sector.
The area covered by the IPC is the whole national territory.
Month.
All measures to reduce errors have been implemented, ensuring the overall accuracy of the index is good. Additionally, there is an average lag of 9.5 months between the provisional and final releases, during which the indicators typically exhibit a consistent trend.
Index.
For each reference month, the estimation method uses information on hours worked from the BWWF, which are bodies responsible for managing various contractual terms at a territorial level. They collect data on the hours actually worked by workers and apprentices in the construction sector.
Through a census survey based on the 106 BWWF in Italy, Istat gathers information monthly on hours worked, on the number of workers and the number of businesses to which hours are referred. Collected data are checked for consistency accuracy. Additionally, comparisons with other Istat surveys have shown that data from the BWWF sufficiently approximate the trend of the labour input of the sector.
The provisional data on hours worked sent by the BWWF are then revalued applying coefficients, calculated on the basis on the deviation observed in the series between provisional and final data. These coefficients are calculated with regard to the geographical division of each BWWF. In general, the variance related to distribution j, for the month m of the year t, calculated for the transmission interval i, is defined by:
where:
The transmission interval i=1,2,3,… refers to the number of months following the reference period for which the data are transmitted; for example, i=1 means that the transmission of data occurs approximately 1 month after the end of the reference month, i=2 means that the transmission of data occurs approximately 2 month after the end of the reference month, and so on.
The revaluation coefficient of the hours of the geographical division j, for the month m of the year t, is calculated as the average of the deviations of the same month in the previous 3 (k) years:
where:
This procedure produces five different revaluation coefficients and five total hours, one for each geographical division.
Subsequently, the total number of hours of each geographical division is multiplied by its expansion coefficient, generating five partial totals of hours, which are then added together to provide the value of the revalued total hours. In general, indicating ∆_(j,m,t)^i as the revaluation coefficient for the month m of the year t, calculated for the geographical division j for the transmission interval i of the data and h_(j,m,t)^ , as the hours worked in the same period and related to the same geographical division j (with j=5), the estimate of the total hours revalued for the generic month m of the year t is given by
The total thus obtained (3) is then adjusted with a monthly productivity coefficient, calculated using the annual National Accounting data (value added and hours worked in the construction sector). Denoting π_(m,t) as the productivity coefficient for the month m in the year t, a proxy of the total value added of production in the construction sector will be expressed by the following relationship:
That means that an estimate of the overall value added in volume for the month m of the year t is derived from the product of the sum of the partial totals of the revalued hours worked of the geographical divisions and the monthly productivity coefficient (4). The overall volume of production thus obtained, represents a proxy for the value added of production in construction (section F). Then, the equation (4) is estimated for the same month of the previous year as well, but in this case, the value of the total hours of the month m of the previous year, H_(m,t-1)^ , will not be a revalued data, as by year t-1, the hours have completed the data revision cycle. The corresponding equation for the same month of the previous year will be:
where:
Finally, the official index for section F is calculated using the chain-linking method, applying the trend change calculated on the value added to the respective index of the same month of the previous year.
where:
Starting from provisional data of January 2024, the estimation method of the IPC has been completely revised according to the EBS methodological manual for compiling the monthly index of production in construction – 2021 edition. The new methodology for calculating the IPC applies an indirect method and it uses as calculation input:
hours worked provided by the Building Workers Welfare Funds (BWWF) in the reference month;
monthly productivity coefficient, calculated using the annual National Accounting data (value added and hours worked in the construction sector);
distribution quotas calculated using the annual National Accounting data and the administrative electronic invoicing data provided by Revenue Agency. These quotas are used to divide the production of Nace Rev.2 Section F and obtain the production of the F41, F42 and F43 Divisions of Nace Rev.2
Although hours worked represent administrative information, data on labour input used for the IPC compilation are obtained through a statistical survey. Since 2016, the survey conducted on Building Workers Welfare Funds (BWWF) has become a census and since 2024 the BWWF have increased from 98 to 106. The trend and the rate of change of hours worked are always aligned, confirming the reliability of this index in describing the evolution of the sector output.
Through the census survey based on the 106 BWWF in Italy, Istat gathers information monthly on hours worked, on the number of workers and the number of businesses to which hours are referred. Collected data are checked for consistency accuracy.
Monthly.
ISTAT provides a provisional estimate of the monthly value of the IPC, typically 45 days past the end of the reference month and transmits it confidentially to Eurostat, which uses these indices in the calculation of the European aggregates. Subsequently, these estimates undergo revision 75 days after the reference period. Provisional estimates are then released at national level approximately 50 days past the end of the reference month. Initially, the data is provisional at the time of first release, with subsequent revisions leading to finalization coinciding with the annual review which typically occurs in March of the year following the reference period when information on hours worked is completed.
Data dissemination at the national level adheres to European definitions outlined in CR 1503/2006, ensuring consistency across the entire national territory in terms of definitions and methodologies. The data used to compile the index essentially covers the entire national territory, as the 106 welfare funds involved in the BWWF survey are distributed across all Italian geographical regions, even if for some of them the response rate is slightly lower than the national average. Furthermore, the quality (completeness) of the data transmitted appears to be less satisfactory for some regions, whose BWWFs collect data on businesses with a delay.
With the publication of the provisional index for January 2024, the new series of non-adjusted data, corrected for calendar effects and seasonally adjusted are released based on the 2021 reference base.
The F series starts from the year 1995:
- for the years prior to 2021, the non-adjusted series were reconstructed through a shift operation of the data previously published based on 2015, in order to keep the trend variations of the original series unchanged;
- starting from the year 2021, the indices have been recalculated with the new estimation method based only on labor input.
The F41, F42 and F43 series start from the year 2021.
