The article could have mentioned the main cause for the recent crazy rise of house prices in Switzerland; the negative interest rate.
Lately the Swiss interest rate has gone up, although not as much as elsewhere, and the effect can already been seen, house prices are dropping.
One effect of this was that big companies and pension funds were desperate for some way to park their money. This lead to the situation that they would build lots of new appartment buildings in metropolitan areas that would remain empty for years, not returning any income, they were just a vehicle to park the money. At the same time, this development was detrimental for the towns, but the towns couldn't do much against it. In the towns, people would move from the old appartments in the center to the cheap new appartments in the outskirts, leaving behind a dead center. (There was an article about this effect in the "Tagesanzeiger" called "Die Huttwilisierung der Schweiz", worth reading.)
We should probably track mortgage payments not valuations over time.
It is still important, since a higher price means a higher down payment.