The Construction Index (ICC) is a conjunctural indicator that estimates the evolution of the production and employment in the Construction sector of the Basque Country. The units of information are the companies that carry out construction work. The Construction Index corrected for calendar effects (number of working days and holidays) offers inter-annually comparable values, while for inter-monthly comparisons, the deseasonalised Construction Index is used (corrected for the effect of periodical fluctuations of less than a year).