Instituto Nacional de Estatística, Statistics Portugal

National Accounts Department/Price Statistics Unit

Av. António José de Almeida
1000-043 Lisboa
Portugal

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.

Households which are owner occupiers.

The main statistical variables are price indices.

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.

The indicator covers the whole country.

Data are available since the first quarter of 2010 for all indexes series.

2015=100

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.

European:

- 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 specifications 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, and amending Commission Regulation (EU) 2020/1148.

National: 

- There are no national legal acts related to the OOHPI

- The production of the OOHPI is included in the annual work programme of Statistics Portugal approved by the National Statistical Council (produced within the framework of the HPI)

Not available.

Statistical confidentiality is one of the basic principles of the Law of the National Statistical System (Law No 22/2008 of 13 May). According to its article 6, all individual statistical data collected by statistical authorities is to be treated as confidential. This Law and other relevant national legislation on this topic (e.g. Law No 67/98 of 26 October on the protection of individual data) can be obtained on the website of Statistics Portugal (http://cse.ine.pt/xportal/xmain?xpid=CSE&xpgid=cse_main&cont_cse=139660987; available only in Portuguese). As any statistic produced by Statistics Portugal, the OOHPI is subject to these laws.

The data are made available at the level of detail described in the OOH Regulation. Access to microdata is limited to the staff in charge of the compilation of the OOHPI. For the specific indexes, no information is available to identify or locate the dwelling or the agents involved in the transaction

The OOHPI is not published in Portugal for the moment.

Not applicable (see 8.1).

Not applicable (see 8.1).

Quarterly (OOHPI) and annually (weights)

Not applicable (see 8.1).

Not applicable (see 8.1).

Not applicable (see 8.1).

Not applicable (see 8.1).

Not applicable (see 8.1).

The OOHPI is not disseminated by Statistics Portugal. Thus, there is no methodology document available for this indicator.

Not available.

Statistical processes and outputs are defined and produced in line with the Quality Assurance Framework of the European Statistical System. Monthly and quarterly routines have been put in place in order to detect and correct errors in the source data files and in the data generation process. 

1.       Preventing mistakes or defects in statistical processes

The weights and price indices have been produced and reviewed against the concepts, definitions and classifications set out in the OOH regulation:

i)     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;

ii)   Commission Implementing Regulation (EU) 2023/1470 of 17 July 2023 laying down the methodological and technical specifications 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, and amending Commission Regulation (EU) 2020/1148.

Situations in which it is not possible to meet targeted concepts are identified and measures aiming at improving these situations have been put in place.

In order not to impose a burden on respondents, administrative data have always been preferred over surveys data to generate OOHPI price indexes and weights. Documentation explaining the processes on the derivation of the hedonic regression results is also available for helping index compilers producing quarterly results.

2.       Preventing mistakes or defects in statistical output

The relevance of produced statistics is checked with main internal and external users (e.g., national accounts department, central bank, administrative data providers). Produced index for purchases of newly built dwellings is compared, as an internal checking procedure, with an index using bank appraisals data. OOHPI statistics are produced in line with the deadlines put forward in the OOH Regulation. In order to avoid data entry and other mistakes, several mechanisms have been put in place at various stages of the production process. For instance, dwellings that have been transacted by less than 20 thousand euros and higher than 3 million euros are ruled out from regression analysis. Moreover, in order to minimize data entry and other errors, a sample of the collected bank fees and insurance premiums is chosen at random every month and checked against first price collection figures.

Not available.

The OOHPI responds to the needs of those users interested in making comparisons of transactions prices of dwellings new to the household sector and other goods and services that households acquire in their role as owner-occupiers among EU member states. Eurostat and the European Central Bank are the main users of the OOHPI information.  

Not available.

The main index covers the whole country and all dwelling market transactions.

Until the 1^st quarter of 2019, for the index covering 'Newly built dwellings purchases', it was not possible to separate household from non-household expenditures (i.e., this index covers the purchases of residential units by all sectors). From the 2^nd quarter 2019 onwards, and as the result of additional and more detailed information made available to Statistics Portugal by the Tax and Customs Authority (AT), it’s possible to know the institutional sector of those involved in the transactions, namely allowing to separate acquisitions made households and non-households.

There are no estimates of the overall accuracy of the OOHPI.

Portugal does not use probability sampling for any of the OOHPI sub-indexes.

Portugal does not produce regular estimates of non-sampling errors and their sources.

The OOHPI is produced and transmitted in accordance with data transmission requirements established in article 7(1) and 7(2) of the 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 (i.e., up to 85 days following the end of the reference quarter). The various indexes are sent up to 83 days after the end of the reference quarter and weights are sent before 15 June of the year following the year to which the weights relate.

The OOHPI is provided one to two days before the transmission calendar agreed with Eurostat.

The Portuguese OOHPI has no regional breakdown.

Data are comparable over time. Take note of the considerations made in sections 12.3 (Completeness) and 18.5.4.1. (Purchases of newly built dwellings - detailed information).

In Portugal there are no other indexes measuring the OOHPI. 

When produced, the coherence of OOHPI is checked against the HPI (and bank appraisals data). In addition, the net weight of the OOHPI, covering the purchase of new dwellings expenditures, is checked annually against its gross HPI weight counterpart. The correlation between HPI and OOH, aggregate indexes, is considered almost perfect.

All figures are checked for internal consistency. Higher-level aggregations are derived from elementary aggregates according to index chaining practices.

One senior statistician is in charge of the compilation of the indicator on a full-time basis, together with the HPI and House Sales. In addition, the production of the OOHPI is supported by an IT expert and an expert in geo information, both on a part-time basis. Assistants and/or administrative staff are employed whenever it is necessary. The senior statistician participating in the production of the OOHPI has more than 10 years of experience in the compilation of real estate statistics and participates in workshops and technical meetings on real estate price statistics. 

The OOHPI is presently not subject to routine revisions.

Not applicable.

See below.

The OOHPI are based on the following data sources:

The compilation of OOHPI weights is based on annual National Accounts (NA) data on gross fixed capital formation (GFCF), which households make in residential structures. The data provided by NA is split into GFCF in newly built dwellings, major renovation works, the service associated with the new and the existing dwellings (i.e., real estate intermediation services) and costs of transfer of ownership. The weights reflect the purchase of structures and are, for this reason net of land values. In addition, weights are corrected from the housing structures that are bought by households for renting purposes. 

It is also used, an additional source of information, derived from the IES (Informação Empresarial Simplificada) or the Simplified Business Information[1], related to the value of insurance premiums purchased and the costs associated with claims, information necessary for the calculation of the weight associated with the index O.1.2.2.

[1] IES is a (electronic) vehicle that companies have to deliver information to Statistics Portugal and other public bodies

The data used in the compilation of the OOHPI indexes is obtained on the basis of the following frequency:

The following data validation procedures are applied:

See below.

See below.

OOHPI is a Laspeyres-type price index.

The first stage consists of the calculation of the five elementary indices (relevant for Portugal), namely:

-        O.1.1.1.1. Purchases of newly built dwellings

-        O.1.1.1.2. Self-build dwellings and major renovations

-        O.1.1.3. Other services related to the acquisition of dwellings

-        O.1.2.1. Major repairs and maintenance

-        O.1.2.2. Insurance connected with dwellings

Once the elementary indices have been calculated the aggregation process for the next levels is initiated. In summary:

i)               The index O.1.1.1. "New dwellings", result from the calculation of a weighted arithmetical average, of the indices O.1.1.1.1. "Purchases of newly built dwellings" and O.1.1.1.2. "Self-build dwellings and major renovations". This index is obtained by the sum of two parts calculated by dividing each quarterly value of year Q by the 4th quarterly value of year Q-1 and multiplying by its weight.

ii)              Then, is calculated the index O.1.1. "Acquisitions of dwellings", that results from the calculation of a weighted arithmetical average, of the indices O.1.1.1. "New dwellings" and O.1.1.3. "Other services" related to the acquisition of dwellings. This index is obtained by the sum of two parts calculated by dividing each quarterly value of year Q by the 4th quarterly value of year Q-1 and multiplying by its weight.

iii)             The following is the calculation of the index O.1.2. "Ownership of dwellings" that results from the calculation of a weighted arithmetical average, of the indices O.1.2.1. "Major repairs and maintenance" and O.1.2.2. "Insurance connected with dwellings". This index is obtained by the sum of two parts calculated by dividing each quarterly value of year Q by the 4th quarterly value of year Q-1 and multiplying by its weight.

iv)             Finally, is calculated the index O.1. "Owner-occupiers’ housing expenditure" that results from the calculation of a weighted arithmetical average, of the indices O.1.1. "Acquisitions of dwellings" and O.1.2. "Ownership of dwellings". This index is obtained by the sum of two parts calculated by dividing each quarterly value of year Q by the 4th quarterly value of year Q-1 and multiplying by its weight.

The compilation of OOHPI weights is based on annual National Accounts (NA) data on gross fixed capital formation (GFCF), which households make in residential structures. The data provided by NA is split into GFCF in newly built dwellings, major renovation works, the service associated with the new and the existing dwellings (i.e., real estate intermediation services) and costs of transfer of ownership. The weights reflect the purchase of structures and are, for this reason net of land values. In addition, weights are corrected from the housing structures that are bought by households for renting purposes. This correction is based on census data on the percentage of dwellings from the total dwelling stock that are rented out.

The weights compilation is consistent with the production of an annually chained Laspeyres-type index, which uses the fourth quarter of the previous year as the linking period.

The weights for the OOHPI are price updated every year. At present, Statistics Portugal is able to provide NA (final) figures of year t-2 at the end of year t. In practice, this means that, as a rule, the OOHPI of year t will be based on NA information of year t-3 (e.g., indexes with reference year of 2023 reflect 2020 NA data price-updated to the 4th quarter of 2022).

OOHPI expenditure share are updated to be representative of year t-1.

Elementary aggregate weights are adjusted with an appropriate price change between the year t-1 and the fourth quarter of the year t-1.

Each year t, indices are calculated with the 4^th quarter of t-1 as base period. Indices are then linked to the previous 4^th quarter index, as defined in the Laspeyres-type index formula.

See below.

Transfer of ownership. The transaction affects the month in which the IMT payment is made (on the day the contract is signed or a few days before).

Not applicable. There is no VAT on building transactions.

Other taxes are not included in the price of dwellings.

Not relevant.

The value of land is included in the price used for the calculation of the index (O.1.1.1.1.) For weights, the value of land is excluded from the National Accounts data, used for the calculation of weights.

Not applicable / non-existent in our real estate market. This type of housing tenure, for which transactions refer to the transmission of a share of the right to occupy and use a certain housing unit in a cooperative, is inexistent in Portugal. (There are cooperatives for the construction of new dwellings; but the cooperative usually ends after the dwelling is finished).

In view of the above, they are not considered in the OOHPI.

Transactions with clearly low (below 20,000 Euros) or high (above 3,000,000 Euros) values are excluded through the definition of thresholds. It should also be noted that some transactions considered as "non-market" are excluded a priori from the scope of the index as they are classified with a specific legal taxable event and not considered in the indicator in question.

Transactions with more than one property are only considered if it is possible to identify the transaction value for each property. Situations where this is not the case are residual. In the equally infrequent situations in which an identical value was assigned to each property transacted, the hedonic model has variables capable of correcting and adjusting such situations.

The scope of the O.1.1.1.1. index only covers properties that have been traded in their totality. This means that properties are considered to be sold as a whole property, or in any other fraction where the sum of these fractions makes up the unit, e.g. two halves, three thirds, or one quarter together with three quarters.

See below.

The ratio of geometric (and arithmetic) mean prices is calculated to compare prices for different companies/ insurers/costs. The average values per company/insurer/cost result from the calculation of weighted arithmetic averages. The indexes are compiled by comparing the current price level with the price level in the base period.

In the cases in which information is collected (information on insurance premiums and bank commissions), the following situations are contemplated:

i) Insurance premiums: whenever collection from company i become impossible for 2 consecutive months, that company (with an online simulation service) is replaced by another that also provides the same service and preferably has a similar market share. When the impossibility of collection occurs at the level of a particular insurance premium, it is replaced by another of similar characteristics.

ii) Bank commissions: whenever collection from bank i become impossible for 2 consecutive months, this bank is replaced by another one that preferably has a similar market share. If the impossibility of collection occurs at the level of a particular commission, it is replaced by another one with similar characteristics.

In the case of the O.1.1.1.1. index, a hedonic method (combined with stratification) is used as a way to guarantee the quality adjustment. 

For O.1.1.1.2 and O.1.2.1. indexes, both calculated using information published by a third party, quality change is taken into account in the sense that the same model (of construction works) is followed throughout time. 

The O.1.1.3 index is composed of elementary indexes that correspond, in general, to taxes applied to the transaction value, and no quality adjustment is made. The exception is the (elementary) index regarding bank commissions. The bank commissions are obtained through online collection, and if in a given month it is not possible to collect a bank commission fee, the bridged overlap method, which imputes the price variation found for the remaining premiums collected for the same financial institution (providing mortgage credit), is used as a default quality adjustment method. 

The index O.1.2.2. for insurance premiums use a similar procedure to the bank commissions index.

The main reason for the failure to collect a price is the technical breakdown of the website from which the collection is made, either for insurance premiums or bank commissions. Whenever this happens, the chain rate of change of an identical product, from the same company, is applied.

The discounts, when detected, are confirmed at different moments in the reference month (2 additional times). This procedure aims to avoid possible errors made during the initial simulation.

The information collected does not cover inducements.

There were no cases in which a product related to the acquisition or ownership of housing was made available for free and subsequently a price was charged. There were no cases identified where a product was made available for a price and was subsequently made available free of charge.

VAT is included in the observed prices (except in the case of the purchase of dwellings).

Not applicable, no seasonal adjustments are made. 

The item 18.5 - Data compilation, describe the adjustment for quality changes.

None.