Italian National Institute of Statistics

Department for statistical production; Directorate for social statistics and population census; Integrated system on economic conditions and consumer prices unit.

Via C. Balbo, 16 - 00184 Rome (Italy).

The OOHPI is based on the ‘net acquisitions’ approach, which measures changes in prices paid by households for the acquisition of dwellings that are new to the household sector and changes in other costs related to the ownership, and transfer of ownership, of dwellings.

The OOHPI is broken down into the following expenditure categories:

• O.1. Owner-occupiers’ housing expenditure;
  • O.1.1. Acquisitions of dwellings;
    • O.1.1.1. New dwellings;
      • O.1.1.1.1. Purchases of newly built dwellings;
      • O.1.1.1.2. Self-build dwellings and major renovations;
    • O.1.1.2. Existing dwellings new to households;
    • O.1.1.3. Other services related to the acquisition of dwellings;
  • O.1.2. Ownership of dwellings;
    • O.1.2.1. Major repairs and maintenance;
    • O.1.2.2. Insurance connected with dwellings;
    • O.1.2.3. Other services related to ownership of dwellings.

The OOHPI covers the expenditures incurred by households for the purchase of a dwelling (which is new to the sector) and the ongoing costs supported by households in their capacity as owner-occupiers.

The main statistical variables are price indices. Transmetted data are the folloving: quarterly OOHPI (2015=100); OOHPI item weights; annual expenditure.

The basic unit of statistical observation are transaction prices of dwellings new to the household sector and of other products that the households acquire in their role as owner-occupiers.

Owner occupied dwellings.

OOHPI covers the entire country but not for all the OOH items. In particular, with reference to purchases of new dwellings and purchases of existing dwellings new to the households, data are available for the whole national territory, excluding two provinces having a different cadastral system (totalizing about 2.6% of Italian population).

Data are available from first quarter of 2010.

The reference base year is 2015.

The following units are used:

- Index point;
- Percentage change on the same period of the previous year (rates);
- Percentage change on the previous period (rates);
- Percentage share of the total (weights).

OOHPI is a quarterly statistics.

• Regulation (EU) 2016/792 of the European Parliament and of the Council of 11 May 2016 on harmonised indices of consumer prices and the house price index.
• Commission Implementing Regulation (EU) 2023/1470 of 17 July 2023 laying down the methodological and technical specification in accordance with Regulation (EU) 2016/792 of the European Parliament and of the Council as regards the house price index and the owner-occupied housing price index.
• 2020-2022 Italian National Statistical Programme - 2022 update, entered into force with the decree of the President of the Republic of 11 July 2023 and published in the Official Journal -general series – nr. 201 of 29 August 2023.

Not applicable.

There are not national regulations which deal specifically with OOHPI confidentiality.

Data treated are confidential and may be accessed only by the staff responsible for the OOHPI when indicated in internal
documents listing people working on personal data.

The release calendar is not delivered because OOHPI data are not currently disseminated by Istat.

Not applicable.

Not applicable.

Quarterly (OOHPI) and annually (weights)

Not applicable.

Not available.

Yes (Eurostat website).

Not available.

Not available.

For the time being there is not OOHPI documentation except metadata.

Quality reports on OOHPI are not available at the moment.

A general quality assurance framework still is not implemented, but continuous efforts to strengthen and improve the procedures of data control checks and adjustment for quality changes are carried out according to the guidelines and standard set out in the Technical manual on Owner-occupied housing for HICP. A reengineering of the production process is on the way and it will make more systematic the quality assurance policy.

Istat monitors the quality of data set provided by Tax Office, the production process and carries out dissemination according to guidelines and standards set out in the Technical manual on Owner-Occupied Housing for HICP.

Potential user needs of OOH are the following: Central Bank and Minister of Economy and Finance as financial soundness indicators with specific reference to owner occupied houses; Economic analysts for analysis purposes; business associations as sectorial indicators.

For the time being user needs and satisfaction are not monitored.

OOHPI fully meets the specifications set out in the Regulation

Estimates of the overall accuracy of the OOHPI are not made.

Not applicable (probability sampling for the OOHPI and/or its sub-indices is not used).

Purchase of new dwellings - HPI for new dwellings is used as proxy (administrative data provided by Tax Office are used minimizing coverage errors; various IT procedures ensure that errors are minimised in the data).

Self build - Data used for index calculation are collected from Istat surveys and already validated.

Major renovations - The same as for 'Major repairs and maintenance'.

Other services related to the acquisition of dwellings - administrative data provided by Tax Office. Extreme values are identified and eliminated if necessary.

Major repairs and maintenance - For materials: data used for index calculation are collected from Istat surveys and already validated. For services: data are validated at territorial level by Municipal Offices of Statistics and centrally by Istat.

Insurance connected with dwellings - The most important insurance companies provide information (they represent on average about 69% of the market share for both insurance class 'fire and natural elements' and 'other damages to properties'). Data collected from insurance companies are checked manually.

Other services related to ownership of dwellings: Data are validated at territorial level by Municipal Offices of Statistics and centrally by Istat.

Time lag between the end of the period to which the OOHPI relates and its production is about 85 days.

Data are transmitted according deadlines scheduled in the  Regulation (EU) 2016/792.

At the time being no regional analysis of the OOHPI is made.

There are not breaks in continuity for OOHPI.

HPI for new dwellings is used as proxy for purchase of new dwellings index (O.1.1.1.1).

With reference to purchases of new dwellings the weight of OOHPI is annually compared to HPI.

External costs in relation to OOHPI (e.g. purchase of data, other external resources) are not incurred. Concerning burden most of OOH price indices are based on administrative data and there are not relevant cost for data collection and no burden for the respondents; the burden is on charge of Tax Office that prepares the data set to be sent to Istat. Production process is carried out by Istat in house and therefore the costs are the costs of the resources dedicated in terms of statisticians and IT experts. Just for data concerning insurance on dwellings there is a limited burden on the main Italian insurance enterprise that is difficult, for the time being, to be estimated. Few data are collected by Municipal Offices of Statistics according to Istat instructions.

Published OOHPI data may be revised for mistakes, new or improved information.

Purchase of new dwellings: the data source is the HPI for new dwellings; provisional HPI estimates are released quarterly and they are subject to revision with new information available the following quarter.

See below.

Main sources are the following:

Purchase of new dwellings: administrative data provided by Italian Tax Office;

Self built dwellings: HICP minor repairs indices  plus construction costs index for residential building;

Major renovations: the index for O.1.2.1 (Major repair and maintenance) is used as a proxy;

Existing dwellings new to households: administrative data provided by Italian Tax Office;

Other services related to the acquisition of dwellings: administrative data and sector statistics;

Major repairs and maintenance: HICP minor repairs indices plus construction costs index for residential building;

Insurance connected with dwellings: ad hoc survey;

Other services related to ownership of dwellings: HICP minor repairs for indices from 2010 to 2014; specific  price index for the following years that is the price index for the Energy Performance Certificate (APE).

Main sources are the following:

Purchase of new dwellings: National Accounts and Building permits survey;

Self-build: National Accounts;

Major renovations: National Accounts and Household Budget Survey;

Existing dwellings new to households: database of notary deeds of sales and database of rents both provided by Tax Office;

Other services related to the acquisition of dwellings: National Account;

Major repairs & maintenance: National Accounts and Household Budget Survey;

Insurance connected with dwellings: National Accounts;

Other services related to ownership of dwellings: report developed by ENEA (Italian National Agency for New Technologies, Energy and Sustainable Economic Development) together with CTI (Italian Thermo Technical  Association - association operating in the energy sector). 

The most recent National Accounts data available relates to year 2020 so they are reviewed and updated to make them representative of year 2022 (t-1). In particular, external statistics have been used that is: data on investments in residential constructions provided by ANCE (Italian Association of private construction contractors); data about real estate agencies activity in the pandemic crisis provided by Cerved Group. Only exception was for Insurance connected with dwellings because National Accounts data are available for (t-1).

Except for "O.1.2.2 Insurance connected with dwellings" and "O.1.2.3 Other services related to ownership" where data are collected monthly, other data are collected quarterly.

Data are collected using different sources:

• Administrative data: they are encrypted by Tax Office and transferred quarterly to Istat using a secure transfer protocol;
• ad hoc survey conducted by Istat for O.1.2.2 "Insurance connected with dwellings";
• local survey, carried out by municipal statistics offices, under Istat supervision and coordination (survey carried out each month in the first fifteen working days) for O.1.2.3 "Other services related to ownership".

Purchase of new dwellings - various procedures ensure that errors are minimised in the data. The following validation checks are made on each record in the source data:

• extreme values are identified and eliminated if thought necessary
• data cleaning is done to remove cases of obviously erroneous data;
• minimum and maximum values are investigated and removed if believed to be suspect;
• regression model is used to detect any remaining outliers. 

Self build - Data used for index calculation are collected from Istat surveys and already validated.

Major renovations - The same as for 'Major repairs and maintenance'.

Existing dwellings new to households - the same as for 'Purchases of new dwellings' (the database used is the same).

Other services related to the acquisition of dwellings - Extreme values are identified and eliminated if necessary.

Major repairs and maintenance - For materials: data used for index calculation are collected from Istat surveys and already validated. For services: data are validated at territorial level by Municipal Offices of Statistics and centrally by Istat.

Insurance connected with dwellings - Data collected from insurance companies are checked manually. When unusual changes on prices or weights are detected than companies are recalled.

Other services related to ownership of dwellings: Data are validated at territorial level by Municipal Offices of Statistics and centrally by Istat.

See below.

See below.

OOHPI is a Laspeyres-type price index.

OOHPI sub-indices are calculated separately and they are aggregated to higher level price indices.

Sub-index weights are based on national accounts data. The frequency of updating the OOHPI sub-index weights is annual. The most recent National Accounts data available relates to year 2020 so they are reviewed and updated to make them representative of year 2022 (t-1). In particular external statistics have been used that is: data on investments in residential constructions provided by ANCE (Italian Association of private construction contractors); data about real estate agencies activity in the pandemic crisis provided by Cerved Group. Only exception was for Insurance connected with dwellings because National Accounts data are available for (t-1).

O.1.1.1.1 Purchase of new dwellings. Weight calculation is based on National Accounts data and Household Budget Survey (HBS). NA provide data on new dwellings including  enlargements. Building permits survey is the source used to split enlargements (to be used for the calculation of the weight for major renovations).

O1.1.1.2 Self-build dwellings and major renovation. Self build dwellings: weight is based on National Accounts data; weights are price-updated by using HICP (minor repairs and maintenance). Major renovation: O.1.2.1 (Major repairs and maintenance) is used as a proxy (see O.1.2.1 sub-index).

O.1.1.2 Existing dwellings new to households. Weight calculation is based on administrative data. Main data sources are notary deeds of sales database and the database of rents together provided by Tax Office. Data are used to identify flows of change in ownership between sub-sectors.

O.1.1.3 Other services related to the acquisition of dwellings. Weights calculation is based on the National Accounts data on costs related with acquisition of dwellings.

O.1.2.1 Major repairs and maintenance. Weight compilation is based on National Accounts data and Household Budget Survey (HBS). NA provide data on major repair and maintenance involving also major renovation. HBS data is the source used for unbundling major renovation (to be used for the calculation of O112b).

O.1.2.2 Insurance connected with dwellings. Weight calculation is based on National Accounts data.

O.1.2.3 Other services related to ownership of dwellings. Weight calculation is based on data used are provided from association operating in the sector (Italian Thermo - Technical  Association  (ATI)).

The most recent National Accounts data available relates to year 2020 so they are reviewed and updated to make them representative of year 2022 (t-1). In particular external statistics have been used that is: data on investments in residential constructions provided by ANCE (Italian Association of private construction contractors); data about real estate agencies activity in the pandemic crisis provided by Cerved Group. Only exception was for Insurance connected with dwellings because National Accounts data are available for (t-1).

O.1.1.1.1 Purchase of new dwellings. National Accounts data refer to t-3; weights are price-updated to the price reference period, the fourth quarter of the year t-1, using HPI for new dwellings.

O1.1.1.2 Self-build dwellings and major renovation. Self build dwellings: weights are price-updated by using HICP (minor repairs and maintenance). Major renovation: O.1.2.1 (Major repairs and maintenance) is used as a proxy (see O.1.2.1 sub-index).

O.1.1.2 Existing dwellings new to households. Weight calculation is based on administrative data. Main data sources are notary deeds of sales database and the database of rents together provided by Tax Office. Data are used to identify flows of change in ownership between sub-sectors.

O.1.1.3 Other services related to the acquisition of dwellings. National Accounts data refer to t-3; weights are price-updated to the price reference period, the fourth quarter of the year t-1. The external weights are price-updated using HICP (Other services n.e.c.).

O.1.2.1 Major repairs and maintenance. Weight compilation is based on National Accounts data and Household Budget Survey (HBS). NA provide data on major repair and maintenance involving also major renovation. HBS data is the source used for unbundling major renovation (to be used for the calculation of O112b). National Accounts data refer to t-3; weights are price-updated to the price reference period, the fourth quarter of the year t-1. The external weights are price-updated by using HICP sub-indices (Minor repairs and maintenance).

O.1.2.2 Insurance connected with dwellings. Weight calculation is based on National Accounts data. NA data refer to t-1. Weights are price-updated to the price reference period, the fourth quarter of the year t-1.

O.1.2.3 Other services related to ownership of dwellings. Weight calculation is based on data used are provided from association operating in the sector (Italian Thermo - Technical  Association  (ATI)). Weights are price-updated to the price reference period, the fourth quarter of the year t-1.

The chaining of the series is carried out by multiplying the quarterly indices (base fourth quarter t-1=100, 6 decimal places) of the current year for the index of the fourth quarter of the preceding year, expressed in reference base (2015=100, 6 decimal places). The frequency of chaining in the OOHPI is annual. 

See below.

Purchase of new dwellings: HPI for new dwellings is used as a proxy (transaction price is the price paid when the final deed is signed and the ownership rights are transferred. Prices are included in the quarter when final deed of sale is signed).

VAT is included in the price of newly built dwellings.

Other taxes are not included in the price of dwellings.

Government subsidies or fiscal incentives are not taken into account.

Land value is included in prices and excluded from the weights.

Housing cooperatives are covered but they are not detectable at the moment.

Purchases of a share of a dwelling property at reduced prices (for example a part of an inherited dwelling) are examples of non-market price transactions; they are excluded from index calculation but included in weights calculation.

Transactions including more than three properties are exluded from calculation.

Transactions of part of dwellings (part of inheritance) are included in weights calculation for HPI; the same database is used for house sales indicators (still experimental).

See below.

Weighted arithmetic mean.

Replacement is not used.

None.

Not applicable.

Discounts and inducements are not taken into account.

These cases are not detectable.

Excluded.

With reference to quality adjustment, for O.1.1.1.1 (Purchase of new dwellings) and O.1.1.2 (Existing dwellings new to households) a mix of data stratification and the hedonic method of re-pricing has been adopted. Re-pricing methods imply the use of a hedonic function to clean prices from the influence of qualitative features and geographical locations. Hedonic function is estimated, usually, for each year y, during the indices re-basement, through a regression model that uses the data of the previous year (y-1): estimated regression coefficients are kept constant for the whole reference year (y). However, for indices of the year 2023, regression coefficients estimated in 2021 were used.

With reference to the others OOHPI sub-indices, no quality-mix adjustment is done.

None.