Three censuses are actually encompassed under this name: buildings, dwellings and population. This statistical operation consists of carrying out the count, and researching the main characteristics, of all of the buildings and dwellings in the country, and of all of the persons resident in Spain. The reference date for this Census shall be 1 November 2011.

The Census has been carried out in Spain every ten years since the end of the 19th century, and conceived in recent years as the Population and Housing Censuses, it enables:

• Ascertaining the characteristics of the buildings: number of floors, state of conservation, year of construction, etc.
• Having information available regarding the dwellings: tenancy regime (owned, rented, etc.), useful area, number of bedrooms, etc.
• And regarding persons: basic demographic characteristics (sex, age, nationality), composition of the households, educational levels, employment situation, information regarding migrations and mobility.

All of the information that the INE disseminates may be used for free by citizens, companies and institutions.

Traditionally, the Population and Housing Censuses have required the comprehensive visit of all households, in order to carry out the population count. For this reason, the most noteworthy difference between the 2011 censuses and the prior censuses is that, on this occasion, it will suffice to collect the information from a sample of approximately 12% of the population (some 5.7 million persons, 3 million dwellings distributed throughout the country), since the operation will use the information available in the Municipal Register and other registers.

Moreover, the 2011 Building Census shall include the innovation of geo-referencing (GPS coordinates of each building), which will enable making their identification independent of possible changes in postal addresses. This will also enable publishing the results of the Census in a more useful manner for users, without the data always having to adhere to administrative divisions.

Firstly, the obligation of carrying out the censuses is set out in several legal regulations:

• 1989 Law on the Public Statistical Services
• National Statistical Plan
• EC Regulation No. 763/2008 of the European Parliament and Council of the European Union, which obligates member countries to conduct the Census in the year 2011

Moreover, the Census provides information on all geographical areas of the country, and is considered fundamental in decision-making regarding education, health care and social matters, etc.

The Municipal Register is an administrative register including registrations, delistings and modifications, pursuant to legal regulations. Said regulation is aimed at guaranteeing its approximation to reality, but also at preserving the rights granted to citizens by the fact of being recorded in the Municipal Register. Therefore, it is required to fulfil a series of guarantees, in order to delist, register or modify a registration of a citizen. The Municipal Register has been revised and filtered over a period of more than 10 years, so that it will adapt to this regulation perfectly.

The registered population figure is obtained from the database of the Municipal Register that the INE coordinates, and it is the result of carrying out a set of processes regarding the registers of each municipality, in accordance with the regulation governing their functioning. This is considered to be the official population, for the purposes determined by its regulations.

The figure from the 2011 Census shall reflect the resident population, in accordance with the statistical definitions established by international statistical organisations, based on the information contained in the Municipal Register, contrasted with other registers, and adjusted from a survey targeting a significant proportion of the population (some 5.7 million persons). The figure from the 2011 Census is the valid reference for statistical uses and international comparisons.

The last Census was carried out in Spain, as in most of the countries of our area, in the year 2001.

Since the end of the 19th century, the censuses have been conducted every 10 years, though there was already a previous census tradition in Spain. This information regarding historical censuses may be expanded in: Historical Population and Housing Censuses

The study scope of this census comprises the whole country.

Regarding the Building Census, a complete circuit shall be carried out, in each municipality, confirming and extending or modifying, as necessary, the pre-existing data for each building, listing the dwellings contained therein.

Regarding the Population and Housing Census, a sample of 12% of the population shall be taken (some 5.7 million persons) from all of the census sections (more than 36,000) into which Spain is divided.

The recommendations of the Statistics Office of the United Nations establish the convenience of conducting population censuses periodically. According to the information from the United Nations, a total of 227 countries will conduct population censuses between the years 2005 and 2014.

Among the countries that do not belong to the European Union (EU), some conduct a census every 10 years (USA, Russia, Brazil, Argentina, China, etc.), whilst others do so every 5 years (Canada, Australia, Mexico, Japan, etc.).

The 27 Member States of the EU have the obligation, established by Regulation EC No. 763/2008, of conducting the Census in the year 2011.

The census methodology in each one of these 27 countries varies: some choose a census based only on administrative registers, some conduct a traditional census, and others, as is the case of Spain, Germany, the Netherlands and Poland, opt for mixed system of comprehensive prior use of the available administrative registers, complementing the information with a sample survey.

It is expected that a first dissemination, of consolidated figures of the population structure (for each municipality, the residents, by sex, age, place of birth and nationality), will be published near the end of 2012.

The detailed use of all of the remaining variables will be made available throughout the year 2013.

The census results will be made public at the same time for the entire Spanish society, and will be availably for query by all citizens, administrations and companies, free of charge, on the INE website.

The wealth of the results will enable a detailed analysis of Spanish society, the dwellings and buildings existing in 2011, which will serve the needs of all.

Decision-making in matters such as education, health care, etc., requires detailed data that will be provided by this census. Likewise, companies may use the results to determine the characteristics of the markets that interest them, etc.

The query system that has already been tested by users in the 2001 censuses has had good results, and we plan to extend its use, with that of systems that enable carrying out geographical analyses of the information.

With regard to Buildings: year of construction, number of floors below and above ground, number of dwellings and locales, state of conservation, GPS coordinates, installations (gas, water, telephone, lift, garage, etc.)

With regard to Dwellings: use (occupied, secondary, empty), type (family or group), surface area, number of bedrooms, heating, availability of bathrooms, Internet access, tenancy regime (rented, owned), etc.

With regard to the Population: variables relating to basic demographics (sex, age, marital status, place of birth, nationality, number of children, kinship ties, etc.), migrations (according to the municipality or country in which the person resided one year ago, ten years ago, etc.), unpaid tasks (household chores, social volunteer work, etc.), information regarding educational level, occupation, economic activity and type of family nuclei and of households in general.

All the above is nothing more than a brief summary of the basic variables researched. The true wealth of the census lies in its potential use with crossings of all types, of these variables, in order to obtain tables, graphs and maps.

The results obtained will be of a quality greater than or equal to that of other censuses conducted previously.

Although the sample operation design might condition, in part, the detail offered in some areas, we can share in advance that, for those population groups (be they municipalities or any other set of different population unions) greater than 20,000 inhabitants, the dissemination shall be similar to that carried out in the previous 2001 Census, that is, with barely any limitations due to the sampling design.