Construction costs are currently skyrocketing

No, the statement was normally to the USA, which is confirmed by the diagram, but now it is no longer possible, which is why the USA now import from the EU.

If transport and CO2 have a price, it regulates itself better. Some market control is also necessary in capitalism. For exports, one should at least ensure that domestic demand is met before it goes to other countries.

What you are writing goes completely against capitalism. Purchases are made where it is cheapest or where production is most efficient. Therefore, a free market economy needs globalization and as few barriers as possible. Protectionism sounds good, but without globalization, there is no welfare gain through cross-border division of labor. And that would especially harm Germany.

No, that is something different. Protectionism classically describes measures to protect the domestic market from cheaper imports. What wrote, however, is that before exporting one's own cheaper goods, domestic demand is satisfied (possibly at a lower price). I don’t know what this is called; it might also be protectionism but not against external market participants, rather against internal ones. Economically, this also makes sense, because otherwise you would cripple one industry to maximize another.

You do that in a war economy, possibly also in epidemic control. Medicines [Vaccines]. But not with building materials, you don't overturn the market like that. If the goods are too scarce, it only indicates that too much of it is currently being consumed. Then it simply becomes expensive. Market participants give up, demand decreases, it settles itself.

No, that’s something else. Protectionism classically describes measures to protect the domestic market from cheaper imports.

Yeah, sure. But capitalism needs free trade and a free market economy. And if a domestic market has to protect itself from cheaper imports, then something is wrong. The domestic market is no longer producing productively enough and needs to restructure to survive. You can’t just respond to that with protectionism across the board. A tax can be appropriate to combat negative environmental impacts from dumping production, but capitalism doesn’t care about the environment.

I don’t know what you’d call that, it might also be protectionism but not against external market participants, rather internal ones. Economically that also makes sense, because otherwise you’d cripple one industry to maximize another.

But then other economies would also respond with protective tariffs. For example China/USA.

"And if an internal market has to protect itself against cheaper imports, then something is going wrong"

The internal market has strict environmental regulations and is accordingly expensive in production, the imports come from countries that have no regulations.
Restructuring then means shifting production to these countries.
Is that what you want?