[EN] Construction industry has a multiplier effect on the economy of each country. Within the construction industry, residential building is the most important: e.g., in Spain, there were 687,000 new residential units built in 2004, which represent 33% of production in construction industry; these figures correspond to 6% of the Gross National Product. The reasons for this boom are: low interest rates, increase of family incomes, demand from immigrants, changes in family structure, perception of housing as an attractive investment alternative, and demand for tourist housing. In Spain, housing prices increased more than in any other country of the European Union during last years. Our work analyzed statistically this evolution and its ca...