Still looking for a catch but havnt found one yet.
The catch is, that your debt increases in euro’s if the foreign currency increases in value. Can you imagine the fun, if your mortgage goes from 400.000 to 440.000 just because the yen increased ? Switching to a different currency within that mortgage sounds nice but you will only do that because of an increase in value (or interest) and then the damage is already done.
However, it sounds very temping to only pay below 2% 🙂 You can try to cover part of the risk by using long running options on the foreign currency that your mortgage will be in. It does show the current state of the spanish market, the banks are creating new products just so the people will be able to still afford the silly prices.
Same situation in the Netherlands, where you can now get a “generation” mortgage. Your parents start paying for your house and you take over, maybe your kids kids will be able to finally pay the house 😉