Construction costs are currently skyrocketing

Just a thought about the environmental aspect: Using things as long as they work is almost always better than replacing them prematurely with supposedly better technology. The production of the new heating system as well as the renovation of the house also causes considerable emissions. Heat pumps also cause CO2 emissions during operation, see the German electricity mix.

I agree with you, I wouldn’t replace something that works. But as long as it works, you should at least take a close look at what kind of heating system is possible. Because when the time comes, a quick decision has to be made. And if it works, the heat pump saves CO2.
A note about renovation: Insulation saves more than 50 times the amount of oil used for its production over its lifetime. I once looked this up for a very specific "insulation is not ecologically worthwhile" thread. The other thing is the economic side. So ecologically, renovating makes sense.

Perhaps it comforts "us" somewhat regarding the increased construction costs that in the fourth quarter of 2021 the prices for single-family and two-family houses even in sparsely populated rural districts rose again by 15.9 percent compared to the previous year. (I read it in DIE ZEIT, which cites the "Statistisches Bundesamt" as the source.)

What exactly does the increase in value of your owner-occupied single-family house bring you? Nothing more than a paper gain.

The increase in value is completely irrelevant as long as you do not sell or cannot sell.

Much more important is the utility value of a property. The criterion here is, of course, the size of the plot. The mini plots in new development areas are completely useless. Hardly any storage space for wood or building materials, no vegetable garden, no fruit trees or a larger greenhouse.

Some don’t even have a cool and dark potato cellar. Keeping chickens or 2 pigs, a slaughter room was once standard in every house.

And here I must of course ask, what do you build with the currently usual high sums. Many even without a chimney flue for wood stoves, etc.

I think in the near future houses will be valued according to their utility value. There will be significant changes.

I think in the near future houses will be valued based on their usefulness. There will be significant changes.

A few months ago, everyone would have laughed at you for this statement. Self-sufficiency is unnecessary, etc. Times are changing, but who still has the knowledge and skills to provide for themselves. Let's hope things return to normal soon.

That means large properties increase in value more? Please don't tell my wife otherwise she will want alpacas :p

Nobody would have thought that today there is neither flour nor oil, diesel costs 2.20 euros, and the cheapest electricity tariff is at 45 cents per kWh.

In this respect, one should face reality.

In the 80s, it was already quite common to equip houses with incredibly cheap night storage heaters. Quick installation, inexpensive heating elements, and no effort with heating or fuels. The kWh at night tariff somewhere around 2 cents. Such houses today can only be sold at price reductions. I predict a similar fate for heat pumps.

But you also have to look at the houses from the 50s. The houses were adapted to the conditions at the time. But there was the corresponding infrastructure alongside. A chicken coop, a barn, utility rooms, vegetable garden, etc.

I would say that I can easily survive autarkic for 6 months on my property. Whether summer or winter. I would need no car, no fuel, and no electricity. I have stocked up my supplies accordingly for quite some time. Even without active income it would be possible.

As I said, circumstances change.