Construction costs are currently skyrocketing

Why not? If I hadn’t had a photovoltaic system last year and paid 24 cents/kWh (+ monthly basic fee?!), I would have paid over €2,000 more. With your assumed €20,000 investment, the system would have paid off after 10 years. If you factor in the price increases that are coming now, even much sooner :p

This calculation doesn’t make sense to me… did you need 50,000 kWh of electricity? You pay 20 cents and your photovoltaic investment and I 24 cents and no photovoltaic… I could go on like this for a long time if prices wouldn’t rise now…

Normal interest (credit interest) and construction loan interest are not the same.

Rising interest rates are not unanimously bad for everyone.

Certainly not for financing home builders, but for saving homeowners, they are.

Those who financed at 1.5 percent and earn 4 percent interest on their savings still make a profit proportional to their capital.

The spread between the financing interest rate and the savings interest rate is usually not very large. Maybe 1 percent. But here too, there can and do exist large fluctuations.

The savings banks report a 97 percent collapse in customer deposits. That is severe.

Many savings bank customers can no longer save or can hardly save anymore. "Half of our customers need their entire income to cover their monthly expenses," said the Baden-Württemberg savings banks president Peter Schneider on Thursday in Stuttgart.

Nationwide, new deposits collapsed almost completely. At the more than 360 German savings banks, customer balances increased by just 600 million euros in the first half of 2022. In the same period in 2021, the savings banks still received 25 billion euros – a decline of 97.6 percent. In the first half of 2020, inflows had still been almost 30 billion euros.

This calculation doesn’t make sense to me … did you need 50,000 kWh of electricity?

you pay 20 cents and your investment photovoltaic and I 24 cents and no photovoltaic … I could keep going like this for a long time if the prices wouldn't rise now …

Sorry, then that was maybe a bit unclear. I pay 20 cents for the electricity that I additionally draw from the grid. The electricity that I generate myself is not included there. If I were to offset the self-generated electricity, I would have been at a price of about 6 cents per kWh last year.
I paid about €500 last year for over 11,000 kWh of electricity, thanks to the photovoltaic system (+ about €200 in VAT for feed-in and self-consumption). If I hadn’t had the photovoltaic system and had paid 24 cents per kWh like you, I would already have costs of €2,640 just for the 11,000 kWh. And normally there is also a monthly basic fee. Thus, I saved about €2,000 thanks to the photovoltaic system last year when comparing to your electricity tariff.

I hope that was a bit clearer now :)

The savings banks report a 97 percent collapse in customer deposits. That is severe.

Many savings banks customers can no longer save or can hardly save anymore. “Half of our customers need their entire income to cover their monthly expenses”, said the Baden-Württemberg savings banks president Peter Schneider on Thursday in Stuttgart.

New deposits nationwide collapsed dramatically. At the more than 360 German savings banks, customers’ balances increased by only 600 million euros in the first half of 2022. In the same period of 2021, savings banks had still received 25 billion euros – a decline of 97.6 percent. In the first half of 2020, inflows had still been nearly 30 billion euros.

Counter-thesis(es):
- Many savings banks customers simply no longer bring their deposits to the savings bank because it is very expensive and slow.
- Many savings banks customers invest instead of consuming savings bank products with negative returns. This could be a special repayment on the house, buying real estate in general, renovation, photovoltaic system, ...
Stocks/ETFs are the new savings book, but there is nothing to get from the savings bank in that regard.
- Many savings banks customers consume after the corona restrictions were gradually lifted at the beginning of 2022 (-> see e.g. travel boom)

I also consider the Sparkassenmeldung to be exaggerated. What savings rates are they even talking about? Sure, anything under 100, maybe 200€ will first be used up (as long as one does not want to restrict oneself too much now, e.g., on meat consumption, alcohol, cigarettes, special items. Maybe the money is then also better available in the checking account than being put away.

Btw....I bought 1kg of regional ground beef yesterday at the butcher in the village. I don't have discount store prices in mind, but it seemed quite inexpensive to me.