Financing - Renovation of old stock with high costs: Realistic?

You have a pretty good income. And if not you, then who? One can actually observe that those who are financially very well off tend to be very cautious. Conversely, some overestimate themselves when the numbers don’t look so rosy. In this sense, I see no financial reason for you not to take the risk.

Nevertheless, I have noticed some gaps that you could pay attention to again.

Moreover, it’s not just the €2,500 per month, but there are also building insurance, water, possibly higher electricity costs, repair costs, etc. So realistically it will probably be over €4,000 per month. Maybe €4,500.

Exactly. A house actually consumes more electricity than a smaller apartment. Garbage, water, supply and disposal. That’s not visible in a warm rent. Cautious people plan an extra €400-500 for that.

Expenses (monthly):

Item Amount Comments
Rent (warm) €900
Childcare €700 Kita + meal provider
Electricity €100
Savings rate €100
Groceries / daily shopping €550
Car €300 Diesel + insurance
Insurances €100
Internet €20
Leisure / hobbies €300
Purchases €400 Clothing, electronics, kitchen appliances, etc. etc.
Travel / misc. €400
Total €3,870

Since you just bought a new used car, you know that you also have to save for a car. As you said: there would have to be a second (reliable) car. Fuel to chauffeur the children then comes on top. Costs for the car could double. Then I would like to link the overview from another thread here:
https://www.hausbau-forum.de/threads/hausbaufinanzierung-einschaetzung-zum-finanzierungsrahmen-fuer-hausbau.48650/
It shows that you also have to pay quite a bit for health, gifts and hygiene. €550, as you mentioned, should be checked by you. And then the insurances: the €100 mentioned I pay only for my old life insurance, accident, risk, liability, supplementary health insurance, automobile and a few others come on top.

Of course, then there wouldn’t be 5,500€ left. 5,500€ would be what’s left if the rent drops now/today, but I (out of negligence) didn’t write anywhere how the situation with the loan then looks like. You can of course figure it out, but effectively it would be the 5,500€ minus the 2,500€ (loan installment) or 3,000€ including additional ongoing costs. So then (5,500€ - 3,000€) 2,500€ remain per month.

8,500€ income minus 2,500€ installment minus 500€ additional costs equals 5,500€ according to my math skills. I don’t know what you’re calculating.

Loan installment + all other previously mentioned living expenses then amount to about 6,000€ per month. From my point of view, that is huge.

Even bigger is that you cover your entire living expenses with that and can still save 2,500€ every month.

And sure, there are still about 2,500€ left monthly to live on, but we just have concerns whether that’s enough

After you have already lived well with, for example, 4,800€ per year alone for clothing and electronics or 3,600€ for hobbies? Are the concerns really serious or are you trolling?

Or with the wish mentioned in the initial post maybe to switch to part-time work at some point,

Something about a prospective wish is stated very briefly. What does that mean exactly in euros? Maybe you could also cut back a bit on the gimmicks (e.g., the mentioned expenses)? Prospectively, the costs for the daycare will also cease.

But (even if that is perhaps hard to understand) such an apparently simple decision is not for us.

Totally incomprehensible to me. Even if we reduce the salary a bit, the financing is a no-brainer.

I don’t understand the problem either. You have a cool project and can really create an individual and luxurious living space. Which you obviously want. That’s cool. Just do it. Others also buy a convertible or two motorcycles, that’s what you call fulfilling wishes and enjoying life....

8,500€ income minus 2,500€ installment minus 500€ additional costs equals 5,500€ according to my math skills. I don’t know what you’re calculating.

I misunderstood your wording. We don’t actually have 5,500€ left, because the fixed costs mentioned at the beginning still have to be deducted from that. But I understand what you mean.

Completely incomprehensible to me. Even if we cut the salary a bit, the financing is a no-brainer.

We have no experience with financing, and if you see it like that, as apparently others here do as well, that obviously helps us. Originally, as a couple, we said to ourselves: we won’t do anything that one of us couldn’t pay alone. I can’t really explain that rationally either. It probably comes from the thought: what if one of us can’t work anymore, or worse?
And neither of us alone can pay the roughly 6,000€ monthly.
But okay, I have understood what the general consensus here is.

We have no experience with financing and if you see it the way others apparently do here, that obviously helps us.

It has been my job for almost 30 years.

I can't really explain it rationally either.

It's also completely right to think carefully about such a life decision. Then play through the worst case scenario with only one earner. What exactly would the income look like then? And what could you save on expenses (keyword: clothing, electronics, or similar). And even worse. It would then no longer fit! What do you do if you have €2,300 cold rent in five years? The same as with a €2,500 installment you cannot pay. Look for a new apartment or new house (yes, selling is not nice, but also not bad). So what. You can "whine" or simply take a life risk. And from today's perspective, that is very manageable for you.

aber da als Wärmeabgabe zu 99% Fußbodenheizung geplant ist,

Underfloor heating is one of the most overrated achievements in residential construction. I no longer have it and have not missed it a single day. In a historic house, there are wonderful other ways to bring warmth into the rooms without having to compromise the style of the flooring.

Ursprünglich hatten wir uns als Paar mal gesagt: wir machen nichts was nicht auch einer alleine bezahlen könnte. So richtig rational erklären kann ich das auch nicht.

There are personal principles that do not need to be explained. That is completely OK and changes the framework conditions. Self-imposed rules can also be changed by oneself. That is completely OK as well.