Why recent crises all started with a housing bubble? I was writing some notes about the last economic and financial crisis and I noticed that all these recent crisis start with a housing bubble. Beside the 2007-08 US's one, also Japanese crisis in the beginning of the 90s and Spain's crisis, just to cite a couple of them, all have started by housing price boosting. 

Why are all recent crisis starting with a housing bubble? Is something related to modern economies or just a coincidence?
In a fractional reserve monetary system loans create money and loan repayments destroy money. Most bank lending in modern times is for the purpose of purchasing real estate. So the amount of money that exists in the economy is closely tied to the enthusiasm for purchasing real estate. You could not really make this kind of statement for any other class of asset - this is why the housing market in particular has such an impact on the economy. During the upswing of a housing bubble the money supply will be growing fast, but when the bubble bursts the money supply will fall (as existing mortgages are repaid) leading to recession. The whole point of QE is to counteract this fall in the money supply.

Confusingly economists use the word "credit" to describe (most of) the money we use in the economy, so many people do not realise that the "credit crunch" was in fact a "money crunch".

Hyman Minsky is the most famous economist that would subscribe to these kind of views. You might also want to look up the term credit cycle.

By the way, none of these views are mainstream. Mind you the mainstream economists did not see the last crash coming, so you should not really expect them to explain what happened.