Seems to be objective evidence that house prices in Canada, UK and Australia are overvalued, while house prices in US, Germany and Netherlands are not.
What you describe doesn't sound like a bubble to me: It's not something that blows then bursts. That's just that foreigners are richer than locals.
Usually this happens when interest rates go up, because then it's better to keep your wealth in a more liquid investment like cash. Mortgage payments go up as well, turning the (imaginary) loss of equity into concrete loss of income.
What might be happening (I think, seen no evidence yet) is that asset managers in banking have moved "safe" money from treasury debt to real estate, because return from treasury debt has moved to close to 0 since 2008. The result is billions of dollars have moved into real estate across the world, fueling what seems to be an increasingly global real estate crisis.
Lots of global cities do have bubbles from foreign investment parking wealth in property, driving up prices and squeezing out locals looking to buy. Here's how it works:
Foreign investors buy luxury properties
Top-tier locals can't buy luxury properties, buy the next highest property class
Second-tier etc.
Lower-rung locals have no properties to buy. Not: they don't have enough money; but the property type they would traditionally occupy isn't available, and no alternatives have been built since it's always in a developer's best interest to aim at the top, in the abscesses of government incentives.