Every household will receive a census form over the coming weeks which must be filled out on the night of April 23rd.
Yesterday marked the beginning of the "field campaign" for the census, which will be carried out by 4,000 enumerators who will distribute a total of 1.5 million forms to all households and institutions.
The 2006 census will also include four new questions relating to ethnicity, family structures, volunteering and births.
The question on ethnicity follows the results of a pilot survey which indicated there was a high level of acceptance of the question from the public. On family structures, people present in the household on census night were previously asked for their relationship only to the person filling out the form.
The new question seeks to ascertain the relationships of all persons present in the household and is aimed at building a more accurate picture of family groupings. People will also be asked whether they have helped or done voluntary work in the previous four weeks, as part of an attempt to gauge the level of voluntary activities taking place in the community.
Aidan Punch, a senior statistician with the CSO, said the figures will provide a benchmark from which to monitor changes over time. A new question on the number of children born alive to women will also feature.
The proposed question is the only source of comprehensive information on women who have had no children. This an area of increasing policy interest.
Preliminary results will be published within three months of census day, with final results made available within two years.
The census will be available in the following 11 foreign languages: Arabic, Czech, Chinese, French, Latvian, Lithuanian, Polish, Portuguese, Romanian, Russian and Spanish. Additional information in the above languages and also Estonian, Hungarian, Slovak, Turkish, and Yoruba - spoken in several African countries such as Nigeria - is available on the CSO's website (www.cso.ie).