Construction costs are currently skyrocketing

Anyone who buys a house from the 70s and wants to bring it energetically on par with today's energy-efficient houses is told by the energy consultant between the lines that they can do it for their green conscience if they like, but financially and despite subsidies it won't pay off. The average residential building in Germany has a demand of around 150 kWh/(m2a) and falls into class E (source: Verbraucherzentrale). This can perhaps still be expected as a standard from the buyer of an existing property, but certainly not the leap from an energy guzzler to energetic modernity.

It doesn't seem to be that far off. Nordanney is also bringing his house from the 60s into the modern age, and I doubt he is putting money in purely out of hobby. I also deliberately left out a concrete number at this point. It is clear that the big jump is from 300 to 80 kWh and any further optimization then has an increasingly unfavorable cost-benefit ratio. But costs do not scale linearly either.
By the way, dealing with average values doesn't help anyone. Anyone insulating the facade will not stop at 6cm just because they have reached the average of all buildings, but will use more material. The effort for bonding and plastering remains the same, whether it is 6cm or 16cm insulation.

So far, energy transition policy has been rather nebulous. Hardly anyone knew what the best solution for their house was, nor what the measures would cost them in total. Only now, as the fog is clearing and people are gaining an overview of the legal requirements, the market and the technical possibilities, having conversations with craftsmen, getting quotes, etc., are they realizing that they won't get away with just a few thousand euros.

I can partly understand that, and I also have little understanding for the back and forth in politics while at the same time creating artificial time pressure (before the summer break, starting 2024...). I am also annoyed by the strong focus on heat generation instead of the building envelope.
But when you look at the end goal, net zero in 20-30 years, it should be clear to everyone that this cannot be achieved with a few small improvements. This is a major effort for the whole country. That has been clear for a long time if one wanted to listen.

And just one thing on democratic decisions. A large part of Germans reject the Building Energy Act (76%).

Sure. As long as it's abstractly about "more climate protection," everyone is for it. As soon as it concerns their own wallet, everyone thinks someone else should pay for it. Cognitive dissonance and the St. Florian principle, after all. This is true for every specific measure proposed so far. Whether wind farms or power lines nearby, driving or flying less, driving more efficient cars, insulating houses...
Only photovoltaic systems on one’s own roof seem to receive approval. At least as long as the bill for the feed-in tariff is not shown separately as a Renewable Energy Act surcharge.

Anyone who buys a house from the 70s and wants to bring it energetically up to the level of today's energy-efficient houses is told by the energy consultant, tacitly, that they can do it for their green conscience, but financially and despite subsidies it will not pay off. The average residential building in Germany has a demand of around 150 kWh/(m2a) and is in class E (source: Verbraucherzentrale). This can maybe just be expected as a standard from the buyer of an existing property, but certainly not the leap from an energy guzzler to energetic modernity.

If we are talking about a completely unrenovated property. Then, just because of the maintenance reserve, one should have between 100k and 150k ready to resolve the backlog of renovation, and investing such an amount in a house without it having positive energetic effects is simply unrealistic. Even in the conservative calculation, before the whole inflation spiral, something in the range of 1€ per m² per year was considered. If the house has 150 m² and is 50 years old, you can roughly see what is necessary for its upkeep.

As a buyer of an existing property, one must almost feel stupid that for their previous decision in favor of the old town center and against sealing off land at the edge of town, they are now being put on a tight rein and required to bring the settlement house energetically up to par within the next 10 years. Especially in regions with already low property prices, banks will not release unlimited amounts of money for this.
Nothing against climate protection, but reason and proportionality must always be maintained.

Could you clarify that? I am not quite up to date with the currently starting regulations, what else besides heating adjustments is additionally planned.

We also bought a house with energy class G (240/sqm) and end up after renovation at B (68/sqm) for the final energy demand (new roof, new windows, insulated basement ceiling, 8cm external insulation from the mid-90s remains).

And on topic, we have the last major item of our renovation on offer: painting work.

Prices net:

Inside:
Felt plaster including primer, grain size 1-1.5mm: 15€/sqm
2 coats with silicate paint: 7€/sqm
Sanding floorboards (3 passes) and varnishing: 30€/sqm
Baseboard: 8€/m

Exterior painting: 2x primer + 2x coating with silicate paint: 16€/sqm

Work charged by the hour: 45€

We found that relatively fair. Previously, we did not accept an offer where the prices were significantly higher (e.g. coatings with silicate paint 10€/sqm). That was almost 40% more expensive with spatula application instead of plastering.

That's exactly it. Political guidelines change every year, but you only install a heating system every 20 years. I’m seeing this right now in the neighborhood. The young family has their prefabricated house from the 80s, which they bought about 8 years ago and have been renovating every year. But they haven’t done a complete renovation. They painted, installed new bathrooms and new windows, but the insulation is not good. And making such a house suitable for heat pumps for €50,000 is now definitely unaffordable for this middle-class family, even with 30% funding. And that wasn’t known 8 years ago. That’s why I am very skeptical and think that people’s life achievements should not be treated like this. They are definitely panicking now. And honestly: there is no heat pump obligation yet, but aside from expensive pellets, there’s not much left. And with district heating, politics only thinks about their own Berlin-Mitte faction with rental apartments and the financially strong investors. Not feasible or affordable in rural areas. The heating law will lead to many social tensions in the future. And whether we will achieve climate neutrality in Germany by 2045 is at least uncertain.

Okay, so they either had a relatively new heating system or a relatively old one when they moved in.

In the first case, they have built up reserves over the past eight years accordingly, since the heating system that was new back then is now older.
In the second case, it was clear that the heating system would need to be replaced sooner or later. Appropriate reserves should have been made for that.

When you talk about €50,000 and heat pump suitability, I assume a renovation to an efficiency house? You can get a KFW loan at 0.01% interest with a 10-year fixed interest period.

Okay, so they either had a relatively new heating system or a relatively old heating system when they moved in. In case one, they have built up reserves accordingly over the past eight years, because the then-new heating system is now older. In case two, it was clear that the heating system would be due sooner or later. For that, appropriate provisions should be made. When you talk about €50,000 and heat pump compatibility, I assume a renovation to an efficiency house? You can get a KFW loan at 0.01% interest with a 10-year fixed interest rate.

Yes, if you qualify for a KFW level with that. But usually, you have to do everything at once for that. We recently had to finance our €48,000 at about 5% because despite all measures, we couldn’t achieve a KFW house, and then the KFW loan is off the table. You then pay several thousand euros in interest on top. You just have to be able to afford it all.

Anyone building a house today assumes a service life between 50 and 70 years. Actually quite little in historical comparison. I don’t believe that the builders of Gründerzeit villas in the big cities assumed such a short remaining service life.

And if we consider that the apartments in these houses, built and planned 150 years ago, are still enjoying growing popularity today, then it wasn’t all that bad.

How do you want to renovate in cities with historical building fabric? For example, I have seen enough in Nuremberg how hundred-year-old sandstone facades with 60 cm wall thickness were then packed again in 15 cm of Styrofoam to be irretrievably lost.

And not primarily to improve energy efficiency but to adjust the rents upwards.

If one had always followed such fantasies as those of Habeck, there would be no half-timbered towns or historic inner cities or building ensembles left today.

While we’re at it. Is there legal certainty for citizens as well? Can I legally demand a district heating connection? Or does the connection and mandatory usage, which has long existed, only apply to the state?

Now they are promoting direct electric heating again. We already had that 40 years ago. And most people also know where electricity prices are headed. They certainly won’t fall anymore.