Property in good condition financable?

Addendum:
: Even if a bank were to give you a loan – it really looks like your inexperience is being taken advantage of here. Please inform yourselves about the topic of buying a house and if you buy the house against all warnings, please have an appraiser inspect it BEFORE THE PURCHASE. You seem to have no idea about the subject...

Very good point, which also kept me awake.
A house from 1997 of course does not have an energy efficiency class A if nothing was done except exchanging the heating system (plus solar) and triple glazing.
But: the heating system as a new condensing unit presumably has efficiency class A. I suspect there was a sticker with a big fancy A on it and the seller told the completely inexperienced young potential buyers: "Yes, that’s something really fine, efficiency class A!"

Correct in terms of content, but I doubt the lending value of 400,000€. Of the 100,000€ invested in the property, 50,000€ went into the garden (a.k.a. hardly valuable). Here any loan-to-value ratio will be broken...

Maybe the property was worth €300k before renovation. If then €100k has been invested, you are being seriously ripped off.
And no, even today no one gives anything away for free, unless it’s a genuine emergency sale (one in a thousand).

How large is the storage of the photovoltaic system? I also produce 10,000 kWh of electricity per year. I consume slightly more than 10,000 kWh of electricity. Still, I buy almost 8,000 kWh of electricity additionally. Total electricity consumption including e-car (in case someone stumbles over the fact that I stated a completely different electricity consumption in the other thread – that was only for normal household electricity.)

What is the planned repayment rate? I think we would apply 3% – if we would even make an offer. With a purchase price of €450k, the lending value would be €400k. You need €500k, so a 125% loan-to-value ratio. I estimate the installment at around €3,000, assuming the bank calculates reasonably and processes the very high risk accordingly.

Are you serious? €50k as a consumer loan with 6% interest and 72 (maybe even 96) months term. That’s almost €1,000 installment per month. Any household cost calculation at a bank would destroy you. That would be a real deal breaker for us if you had such a consumer loan in addition to the construction financing.

Another big minus point – wanting full financing but additionally having debts.

I would be interested to know how efficiency class A was achieved. A non-renovated house from 1997 is energetically identical to a new building in efficiency class KfW 55? How does that work? I mean, besides a faked certificate (e.g. taking the total area of the house including unheated basement/attic and distributing the energy consumption over this area).

These things must be deducted by a bank from the purchase price to determine the value of the house. If done properly – normally, with such a small financing this doesn’t show, since the lending value is determined automatically anyway and no appraiser is needed.

[*]The first point could certainly be true. Therefore, we would have it checked later by an appraiser or a professional craftsman.
[*]Regarding the second point, I already mentioned in my previous answer that the information has so far only been verbally conveyed by the realtor, without concrete figures or proof. This would happen in the next step, as soon as the bank commits to a certain amount and I qualify as a buyer.
[*]Currently, we are planning financing with an interest rate of 1.8-2%, as we do not intend to rent out the property.
[*]Check24 suggested this option to us. On Monday, we have appointments with my house bank and Interhyp, hopefully to find better alternatives, since I do not like this solution either and would rather wait.
[*]Nowadays, it is probably hardly avoidable. Currently, I still have a car with €45,000 outstanding (hence the monthly installment of €475) and a kitchen that I bought 2 years ago and have almost fully paid off. If the ongoing costs for the property turn out to be too high, I would consider changing the car. That would also yield a larger sum back.
[*]I have already explained more about that in my previous answer.

Nowadays it is hardly avoidable. Currently, I still have a car for which 45,000 euros are outstanding (hence the monthly installments of 475 euros) and a kitchen that I bought 2 years ago and have almost completely paid off. If the ongoing costs for the property become too high, I would consider changing the car. That way, I would also get a larger sum back.