The Statistical Office in Warszawa, using the experience of the Centre for Administrative Data Sources and the Mazovian Centre for Regional Surveys, has prepared an experimental work on the generation of young Polish adults living with parents. The skillful use of administrative data in conjunction with innovative methods for determining families and identifying populations, developed in the Demographic Surveys Department of the Statistics Poland, gave surprising results. We have managed to create a very detailed picture of a certain segment of the population of the country's inhabitants in the scale of gminas and individual years. So far, studies by sociologists and statisticians have been based solely on the representative method. Administrative sources made it possible to draw an experimental portrait of the entire generation of young adults living with parents in Poland.