EH 790K€, financing 480K€ - feasible with our monthly budget?

Yes, that's correct. About 30k EUR with storage :-]

leave out the storage, it is rarely worth it. The size of the solar system can be influenced by roof orientation, dormers, angle

Exactly. We are talking about someone with 8,000 EUR net and 2 children, who wants to buy and build a plot of land worth almost one million EUR in total in BaWü. We are not talking about the chief physician or minister couple, who together bring home 20,000 EUR net ;) 8,000 net is a lot of money. But with the current construction prices and interest rates, it is actually no more than 6,000 EUR net from 2 years ago.

Now you are the one who is totally out of touch. 8k net is more than double the average. There may be people who, with that income, settle for the Town & Country standard, painting themselves and laying floors. That is absolutely not the norm. If someone wants to have their calculation questioned, that must also be taken into account. In the end, the OP can decide for themselves whether their building description matches their wishes. They should only be aware that 3000€/sqm is not as generous as it seems. Especially with the current construction costs.

I believe the winner in terms of craziness has long been determined?
Whoever calls a KfW40+ house "a relatively normal standard, not luxury" has basically qualified for it uncontested...

As I said. 8,000 EUR net today is 6,000 EUR net in 2019.
House prices in 3 years up by a good 30-40% and the monthly installments have more than doubled due to the high interest rates.

You can try calculating whether you could still finance your house today. I definitely couldn’t anymore. And in good years, we are also beyond 6,000 EUR net due to my external work...

PS:
Or rather, I could still finance it, but would have to give up so much that it wouldn’t be worth it anymore. Then you only live for this box...
PPS:
Because do you think someone who earns 8,000 EUR net wants to end up with no money left for vacation... or for the children’s riding lessons? ;)

"relatively normal standard, no luxury"

I did not say relatively normal:

Standard is not bad now

But it is definitely not luxury class. Proper building technology was more important to us than any large-format tiles, smart home, air spaces, lift-and-slide doors, or the oak staircase. I probably would not have taken some parts (e.g. geothermal energy) either if it were not in the GU’s standard. Still, the house was cheaper than many other providers. PS: we could not finance it today anymore. So much would have to be left out so that everything remains affordable at 4% interest, but not necessarily. About ~100k would have to go, completely unrealistic to make that up by worse equipment, especially since the regulations now require EH55 and photovoltaic obligation. And downsizing does not help much for us anymore. PPS: last part of the discussion. I think the original poster can now question their calculation themselves. The most important thing is to be honest about your own wishes from the start, otherwise it will still be expensive afterward and even more expensive than if you plan it properly from the beginning.

The net incomes sound healthy to me at first. When planning needs, you can of course only make approximate plans in advance. The question with the banks will probably be, what loans and other liabilities do you already have? Do you already own property or have debts? I would first get some advice and try to get feedback on my plans.

Hmm, - 2 cars because of village location - 4 people in the household - our wish that besides the instalment there is still enough money to live on, sometimes with a vacation and a new phone - need for security that the instalment is chosen so that a change to a lower-paying employer, economic-related lower salary, age-related reduction of working hours can be managed without endangering the financing. Basically, we choose 2400EUR/month, just via annual special payments. Planning regularly more over a long period makes me uneasy at the moment (I am currently growing into the topic ;-)

I understand, you want to have a buffer as security in case unplanned expenses occur. However, prepayments are usually not free of charge at most banks, so you end up paying extra. Have you compared offers to see if you can maybe find a middle ground?

I think the winner in terms of craziness has long since been determined? Anyone who calls a KfW40+ house a "relatively normal standard, not luxury" has basically qualified for it uncontested... As I said. 8,000 EUR net today is 6,000 EUR net in 2019. Prices for houses in 3 years have increased by a good 30-40% and the monthly installments have more than doubled due to high interest rates. You can try calculating whether you could still finance your house today. I definitely couldn’t anymore. And in good years, we’re also beyond 6,000 EUR net because of my job away from home... PS: Or rather, I could still finance it, but I would have to give up so much that it would no longer be worth it. You then only live for this box... PPS: Because do you think someone who earns 8,000 EUR net wants to end up having no money left for vacation... or for the children’s riding lessons? ;)

Where did you finance? Are there still options to build today at all or can no one afford it in the end?