Europeans get xenophobia all wrong. They freak the fuck out about minarets but do nothing to keep foreign speculators and billionaires out of their real estate markets.
If you want a decent life in your town, keep the despots and oil sheikhs and drug kingpins the fuck out of your real estate market.
It's not the speculators or billionaires, it's the governments.
I saw the same thing in Italy when I lived there in the 90s - any kind of real estate was much more expensive than it seemed like anyone would be able to afford.
Never did figure it out - in the US, the public policy issue with homeownership is making mortgages easier or harder to get. If they're easy, then prices go up but more people own something. If they're hard, then prices go down (because no one bids them up) but fewer people own. I can't figure out a policy that leads to high prices and low rates of ownership.
Restricting affordable housing so that it doesn't grow as fast as population. In the UK the rise in the price of housing is expected to hit 7%, whereas inflation is supposed to maybe get as high as 2% over the next two years. This should give a property bubble in the southeast before the next election, which the government can claim represents an economic recovery.