Is financing advisable despite a high account balance?

The opinion is this: Many families with 2-3 children live in 3-room apartments despite two full-time jobs because they can no longer afford more. Why? Because singles who have money lying around just buy/build a house even though they don’t need it. This totally screws up the market. Of course, they may/can build and do whatever they want. From a global external perspective, a better distribution of sqm per person is desirable, isn’t it? I didn’t/don’t want to talk anyone out of anything here.

In my opinion, the problem lies somewhere else entirely and not in the fact that singles buy a house. When I look at our new development area, out of almost 50 houses, only 1 single has built a house and in total maybe 5 childless couples/retirees. The rest are families. Do you really believe that the problem could even be remotely solved if families lived in these 6 single-family homes?

From a global external perspective, a better distribution of square meters per person is certainly desirable?

That may even be true. But how do you want to do that and the much more interesting question would be, how do you want to enforce it?

The opinion comes from this: Many families with 2-3 children live in 3-room apartments with us, despite two full-time employed persons, because they can no longer afford anything else. Why? Because singles who have the money lying around just buy/build a house even though they don’t need it. That totally messes up the market. Of course, they may/can build and do what they want. From a global outside perspective, a better distribution of square meters per person would be desirable, wouldn’t it? I didn’t/won’t talk anyone out of anything here.

I haven’t read such nonsense in a long time. Those who can’t afford more than a 3-room apartment also couldn’t afford more if the single person didn’t build.

Municipalities often release residential areas "onto the market" that can only be obtained with registration, waiting lists, etc. These are subsidized and only available with a certain number of children or other social components. A childless couple, let alone a single person, hardly has any chances there. Is that the solution? At least for municipalities, because they know which target groups they want to "invite" to their community.

If I extend this thought, someone whose children have moved out and whose spouse has died must urgently leave the property and hand the house over exactly to the family who could not afford a single-family house. Tsk!

The best solution still works with a mixed principle of age and number of children.

"Because singles who have the money lying around just buy/build a house even though they don’t need it...."

A single person also needs living space. And they have the right to self-determination. Your sentence reveals envy.

Putting this statement aside, it is the age and mobility of the OP that decide whether he becomes inflexible with a property. Two singles in our area have also built houses – all at a nice age of around plus/minus 50 years: They all had the need to settle (possibly after individual fateful paths) and have now found it in their houses – there aren’t even 3 rooms empty because they know how to live and don’t slowly fade away in their single status.

: You hit the nail on the head. There really is nothing more to add!

I have completely missed the point now. It's about financing despite high equity.

And that has already been said: you can't deduct anything anyway with owner-occupation.
In the case of a semi-detached house, where half is rented out, it looks different. but I would consult a tax advisor for that.