Construction costs are currently skyrocketing

Since you are specifically referring to me: What exactly is your concern? What changes with a central register regarding the data that the individual authorities already have anyway? I really want to know. And where do these massive doubts about our system of government come from? Just because a few prime ministers acted somewhat clumsily during the corona period?

You misunderstood me: I am 100% committed to our state and legal system. And precisely because of that, I have also seen problematic developments. It started with a partial circumvention of the materiality theory, went through massive procedural errors in the promulgation of regulations, up to the aforementioned prime minister who questions the constitutionally anchored principle of proportionality. And that as the highest executive authority in his federal state. Then the cumbersome way of legislation was repeatedly criticized by the individual state governments and that it was not possible to "govern through." Sorry folks, but all this has very concrete and terrible reasons behind it and, in my opinion, should not remain the case in an alleged crisis situation. Regarding data protection: My problem with central registers is that not just any authority employee has to be able to access every piece of information about me. The possibility of abuse simply grows immeasurably. Likewise, I am absolutely against a central vaccination register. It simply does not concern anyone what I decide. I want to remain as anonymous as possible if I choose to. It is probably known that existing data is occasionally (not systematically) abused. By the way, data protection is not unassailable either. The legislator can change and enact corresponding laws at both the European and national level. And the current regulations still seem to be (for now) in the interest of the democratic majority. On the topic: I also observe that old houses in need of renovation remain listed on the portals longer. The prices would have been audacious even before the war started. So it seems that the owners still want to quickly get rid of half-ruined properties at high prices. It just doesn’t work anymore.

Regarding data protection: My problem with central registers is that not every random authority employee should have access to every piece of information about me. The possibility of abuse simply grows immeasurably.

You are right about that. On the other hand, this does not mean that data cannot be synchronized from one agency to another. I find it absolutely inappropriate that in 2021 I still had to take birth certificates to various other offices. This could be easily solved by the registry office simply notifying the tax office, etc. via push that someone was born. But even within a single office, synchronization is not done properly. When switching to the electronic income tax card, I suddenly found myself back in the church. At some point the data was transferred, and changes were not synchronized from income tax to payroll tax data...

Does anyone have a guess or explanation why there are now more existing houses online? Are they emigrating? Have they lost their jobs and can no longer pay the rate? Do they want to quickly get a lot of money for the house before prices collapse?

My problem with central registers is that not just any government employee should have access to any information about me. The potential for abuse simply grows immeasurably.

However, this could be circumvented by requiring some kind of approval for the query from oneself (e.g., via email link "For example, Mr. xyz from the xyz authority wants to access your current income data, do you agree?"). There are certainly many ways to handle this properly, but I lack the belief that, with all the prevailing skepticism and all the regulations like GDPR, something like this will ever be implemented.

A few years ago, I saw a report where something similar was already successfully practiced in another country. Unfortunately, I no longer know which one it was. Either a Baltic or a Scandinavian one.

Either directly or upon request. You have a legal act with Agency A and are asked whether the data should be automatically shared with Agency B-M (individually) or whether you should be asked again upon request, or if it should never happen. Two years later, you want Document X from Agency B and had checked "upon request" back then; suddenly there is a request in your federal user account asking if the following data may be sent to Agency B, valid only for now / forever... Check, confirm, or decline. Done. It’s all possible already.

Does anyone have a guess or explanation why there are more existing houses online now? Are people moving away? Have they lost their jobs and can no longer pay the mortgage? Do they want to quickly get a lot of money for the house before prices collapse?

A very general assumption, this varies greatly regionally.

I think there is also a lot of uncertainty/fear in the market (similar to the beginning of the pandemic). Potential buyers are reacting very cautiously; it will take some time until the new situation (higher interest rates) is accepted and the market picks up again.

I do not believe in an imminent price collapse; equity returns are still too high despite the increased interest rates.