Which building regulations make new constructions so expensive?

It is too simple to blame only the NIMBYs. The cities also have their own share in this. The Hafner will probably soon be in double digits in planning years, and not a single excavator has rolled yet. Instead of simply starting to build housing that has been needed for 10-15 years, there is constant reconsideration of how to make everything even more ecological. With neighborhood garages, local heating networks with geothermal fields... in the meantime, young families move out of the city and commute very uneconomically to Konstanz. This of course also drives up costs, even if it is not a federal or state regulation. I think we are getting closer to the problem there.

Good. Now imagine the opposite, the China practice. There it is decided that more housing is needed, the boss points to the map and says "Yes, look, THAT spot is perfect!".

Unfortunately, your house is exactly there...

In China, the next day a sign would hang on your door saying something like "We are building a residential complex for 25,000 workers here, the bulldozers start rolling in 4 weeks, pack up your stuff. As compensation, you will get an apartment in the new complex."

Better to have building determination and objection procedures... right?

And in China, the bulldozer comes too. It flattens your place, even if you are still inside.

That is the eternal question. Individual versus society. Somehow we have to manage to make the individual work with society and society for the individual and vice versa. I don't know how either, but I fear we humans can only act in extremes.

Does not work. At best, there is a good compromise.
That is already dictated by the person themselves.
There is a small portion of very smart, a small portion of very dumb, and a large portion of averagely intelligent people. Gaussian normal distribution.

If you put them all in one class now...

It simply doesn't work, which is why we have a three-tier school system.

To be fair to everyone... it doesn't work.

Now you're exaggerating again. It's not about tearing down other people's houses to build apartment blocks. It's about growth on the outskirts of the city that doesn't happen because normal is not good enough. And every two to three planning rounds you have to start over again. The majority for an expansion would certainly be there; the Konstanz housing market urgently needs major relief.

Why don't you start on the other side?
Just imagine, right next to your nice single-family house in a cozy location, they planned a 5-story building. Because it's a good location.
You would also protest.

Or they plan a high-voltage line or a railway route... or a highway, or a road, or a wind turbine, or a factory right in front of your door. You would just accept it with
"It is what it is. We need it, so it has to be built there?"

That is what you ultimately demand.
If it makes sense, it should be built there, no matter what the residents say...
Oh right, hehe... of course only as long as I'm not the resident ;)

Because the electricity comes from the outlet anyway, so I don't need wind turbines in sight... right?