This lady was living in a very desirable, central area of Madrid, paying peanuts for rent. Think Central Park rent for $500.
The spanish public generally doesn't want to, "build more", as they reject megacities. One of the biggest problem is there are no good, viable second and third-tier cities that have jobs. While there are very cheap places on the countryside, no one wants to live there as there are no jobs.
A complex solution would help: Canada-style ban of non-resident ownership, at least in stressed areas, "building more", but not in Madrid, Barcelona or Valencia, and in parallel, boost small businesses and remote work to help de-centralize living. However I don't think any country really cracked the code how to fix housing.