The BBC reported that 10% of the entire Spanish economy (GDP, or gross domestic product) is related to the building industry at it’s peak. That includes estate agents, suppliers, raw materials etc.
The Spanish economy could therefore shrink (ie a recession) once the property meltdown gathers pace, so the people in Madrid are quite right to take this seriously. However they are 10 years too late. I would hope that lessons would be learned, but fear that they may not be.