Construction costs are currently skyrocketing

We are now looking partially 20 years or even longer into the future.

Anything could still happen. In recent years, the trend has been towards urban centers. If this continues over the next decades, it would of course affect the prices of existing properties in "rural areas." But the opposite is just as true. Those who move away from somewhere have to find accommodation elsewhere. At least as long as we don't start stacking ourselves in bunk beds.
Then the price structure shifts further from the countryside to the city. Which does not necessarily mean that less construction would take place. But maybe only elsewhere.

And since we're talking about long-term trends, who says that this strong trend towards urban centers will persist? Maybe the construction of single-family houses in urban centers will actually be restricted or simply no longer be possible. Thanks to home office and widespread expansion of fiber optics, the way of working in the future will continue to change. Then the board of directors will dial into the board meeting from the Swabian Alb, the Mecklenburg Lake District, and somewhere in the middle of the Lüneburg Heath.

There will always be fluctuations. As far as construction costs are concerned, I see no major trend reversal in the short and medium term. It may be that this quarter escalates somewhat, and I would not be very comfortable if I had to build now. It might settle down a bit again but continue developing at a high level.

There is currently a lot of demand.
There is currently a lot of money.
Interest rates are low.
Construction capacities are more than fully utilized (I mean the craftsmen, not the material).
The economy continues to recover.

So where should it come from?

Inflation? Yes, some people bring out the bogeyman. Currently a bit higher, but calculate out the effects of last year’s raw material price increases and the VAT increase at the turn of the year. Then, practically not much has happened.
We have complained for years that we have too little inflation. It's also not a drama if it is temporarily higher. I don’t see inflation high enough on a permanent basis to trigger anything.

Keyword national debt. I see it the same way. How do you get off that? Certainly not by repayment. So devaluation. But we are back to long-term matters here. By the way, if inflation is at 2% and the interest rate at 0% or -0.5% - what do we then have? Right, a devaluation. So it is already happening.
It’s a bit crude and actually more complex, but the trend goes in that direction.

We are now looking 20 years or even longer into the future in some cases.
[...]

There is currently a lot of demand.
There is currently a lot of money available.
Interest rates are low.
Construction capacities are more than fully utilized (I mean the craftsmen, not the materials).
The economy is continuing to recover.

So where should it come from?

Inflation? Yes, some are dragging that bogeyman out of the basement. Currently somewhat higher but just calculate out the effects of last year’s raw material price increase and the VAT increase at the turn of the year. Then, in fact, not much has happened.
We have been whining for years that we have too little inflation. It’s no drama if it’s temporarily higher. I do not yet see inflation persistently high enough to trigger anything.

How do you come to the conclusion that it is "temporary"? The ECB just stated today that inflation in Germany can certainly be above 3%. Asset inflation is now slowly embedding itself everywhere – we have already discussed wood, meanwhile iron ore is becoming scarce. Interest rates are rising, uncertainty is increasing. And CO2 taxes will definitely not be lower next year. Transport costs continue to rise. And then there is the difficult situation in the upcoming cold war, in which Germany (as history’s irony) has once again maneuvered itself into a frontline state status.

But of course, there are currently also positive signs – good sentiment on the barometer, best indicator value since Feb. 2000 – but as a reminder: in March 2000 the dot-com bubble burst. And commodities went as crazy as today only recently in 2008 – shortly before the US real estate credit bubble burst.

So where should it come from? Good question – it remains exciting and time will tell. In hindsight, we will all be wiser. ;)
Only one thing is certain – business as usual does not seem to be the case right now..

How do you come to the conclusion that it is "temporary"?

I've already written that. Because we had special effects. For example, the VAT reduction last year. This year everything is more expensive due to the VAT increase compared to last year. Last year we temporarily had negative values, among other things, so deflationary.

DotCom? Just compare corporate profits or valuations back then and today.

Transport? I wouldn't limit it to transport alone. Sure, we have bottlenecks. Also partly special effects here. Covid, Suez Canal. If I remember correctly (without checking), globally we are not yet back to the economic output as before COVID. Why shouldn't the world be able to handle that logistically again?

Do we see higher inflation in between? Yes, I think so. But then we have maybe 2-3%. I don't believe a bubble bursts because of that.

Keyword "temporary"

Because we had special effects.
For example, the VAT reduction last year.

Yes, we had special effects. And we responded to them with a lot of money, which we put into circulation. I agree with you that parts of the economy weathered the "special effect period" very well. Many companies streamlined and worked on their efficiency. What we will only see in Germany with a delay is a wave of insolvencies (temporary change of reporting obligation) and rising unemployment (short-time work allowance until the end of 2021). These special effects will occupy us for a long time.

I don’t believe a bubble will burst because of that.

I also don’t believe a dot-com crisis-like bubble will burst. Our challenges have not primarily arisen from speculative fantasies, but from years of continuous willful blindness to macroeconomic challenges – under the guise of business management thinking in macroeconomic areas and creative management of the figures to be published. Added to that is the trend of simplistically distancing oneself from complex contexts and facts. On top of that, an increasingly crude understanding of democracy, which through an emotionally social-media-hyped controlling majority dictatorship without minority protection leads to a nebulous, wavering atmosphere that results in no genuine discourse for necessary solutions.
It is time for disruption in many areas. This will act both corrective and drastically.
My only concern is that this will be borne on the shoulders of the weakest. And here we are again at the topic of the thread:
Prices are rising noticeably – not only in the construction sector.
The market regulates prices, but not participation in the market. Increasingly, people are being excluded – not only from the real estate market.

The topic has now arrived in politics.

Interesting article in the WiWo "Wood is becoming scarce: Are export restrictions coming now?"

The topic has now reached politics. Interesting article in the WiWo „The wood is running out: Are export restrictions coming now?“

But Altmeier has excluded that. Something definitely has to be done.