Building new homes is always a delayed by a few years because homes dont just appear.

Secondly its very easy for people to move, while homes are fixed to the ground.

These are just too examples why in this modern age of constant change, there will always be a housing crisis. Looking at the world, its not only Spain with a housing crisis - its basically every single country and the cause is "change".

THis "change" and movement of people means the building of homes can never win, because it takes years to build a home and the supporting community of schools and hospitals.