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

Even with two toddlers. It’s possible, although exhausting, intense, etc., but it works and has many fulfilling moments (for the whole family).

Whether the two toddlers will really consider it fulfilling they will say when they are able to speak?
An acquaintance of ours sold his house and bought a three-sided farmstead, which he wanted to renovate nicely. I remember his plans with the horses there, etc., which I really liked.
He now lives there but apparently ran out of money on the way there and now lives there differently. Nevertheless, they live there and are or seem completely satisfied, and that’s what really matters. The children, however, have left the house or partly live with them again now.
For me, this would not be an option here, because after the renovation having a significantly lower value would have to really offer maximal and very special reasons on the pro side why I should do it.
In fact, you would have to see the property in pictures so that everyone can really classify the statement made here. Likewise, one would have to evaluate the truly existing ability and willingness to provide permanent personal effort.
I once witnessed the expansion of such a building live and then moved in there, but that was really a gem located in a castle garden and by no means worth less afterward.
The owner has a small construction company, did this somehow on the side with 1-2 men and therefore knew all kinds of people and had all conceivable materials lying around somewhere from another construction or purchase, etc., to implement it as a side project.
As a private individual and still with two small children and the thought of wanting to reduce my working hours once, I would not want that.
As so often, context plays the most important role, which can make this project a lifelong dream or a life drama with terrible consequences. I would imagine the worst-case scenario of permanent work effort also with financial pressure and many disappointments also for the family. If I still wanted exactly this property then, I would do it, but only then and if I no longer had any doubts for myself.
The difference with this project is that you cannot quit halfway or, with private changes, you cannot really sell it further appropriately to possibly reorganize your life.

They have two toddlers, how do you imagine that?
Poor children

I can imagine that very well, as I know this situation well from a friend; during the course of the do-it-yourself project, the number of children increased from 3 to 8. None of these children could even remotely be described as "poor children," although the financing of the project repeatedly brought surprises and setbacks (including fire damage in a just completed area).
For me and my family, this would not be something due to my personal attitude towards large craft projects (discipline, perseverance, joy in the activity), but I do not take myself as the standard.

Yes, that is probably the biggest problem and logically no one can make a well-founded statement about it here.

With such a project, you make a calculation—knowing that it will not turn out 1:1. The uncertainty requires more or less courage and self-confidence depending on the financial situation. Much can be compensated for by doing more yourself. Some things simply cannot. The responsibility for the calculation lies with the builder, as they make the decisions. Blaming the architect is a mistake just as blaming the tax advisor for one’s own finances is. Building is for adults who are willing to take responsibility for the consequences of their own decisions. Those who think "childish" full coverage and tend to blame others will inevitably encounter problems—and even more so with such a renovation project than with a new construction.

We really had to listen to a lot, and one of the bigger challenges was to stay stable and just let the others talk.

It was the same for us during the new construction—it doesn’t matter as long as you are not attacked. The latter can be quite well avoided through communication. Those who step out of line and say "I don’t care about the others" provoke. Those who step out of line and keep communicating will be integrated as a welcome change or at least left alone. It is not the project that provokes, but the people carrying it out and their behavior.

As so often, context plays the most important role, which can turn this project into a dream come true or a life drama with severe consequences. I would imagine the worst case of sustained workload along with financial pressure and many kinds of disappointments also for the family. If I still wanted exactly this property then I would do it, but only then and if I no longer had any doubts for myself.

I can agree with that 100%.

Honestly? Based on the description including the ceiling height, that would have been my plan for years.
To sink so much money into such a property for the sake of hobby wouldn't be for me.

Yes, and that is absolutely understandable.
You can tell there are many different opinions here and the "critics" do not have unfounded criticism.
The discussion here is very exciting for me in any case and I am grateful for all honest opinions, whether pro or con.

Of course, the desire to restore such a property cannot be explained purely rationally. It takes a bit of romantic idealization and certainly also a bit of naivety (some call it courage) to do it anyway.
We will think about it intensively again, but especially contributions like the one from fit quite well with my, or rather our, state of mind and encourage us more than the opposing voices discourage us:

It is probably a matter of personal taste. Some see only sweat, dirt, drafty windows, sticking doors, uneven floors and a money pit in such a project. Others see adventure, a life mission, the preservation of historically valuable substance. My family was always from the "romantic faction," the OP seems to be the same judging from his posts. In my experience, the apple often does not fall far from the tree, so I wouldn’t assume this will be nothing but great suffering for the children.

No one can give you a one hundred percent guarantee for success and the fulfillment of your own wishes within your financial means in a project like this. I have read, understood and acknowledged all concerns and counterarguments. Of course, you can also build with significantly less risk. That is clear. It is also clear that a lot of frustration will surely come our way, perhaps even a time full of doubt and bad moods. But at least today, now, this thought does not scare us off.

The core question for us was above all the financial feasibility. That still hasn’t been definitively answered, but reading the discussions and contributions definitely helps us move forward. As stated beforehand, extremely many details are lacking here to actually evaluate this well. So we don’t expect that from anyone.

With such a project you do a calculation – knowing that it will not turn out exactly as planned. The uncertainty requires more or less courage and self-confidence depending on your financial situation. Much can be compensated by an increase in your own labor. Some things cannot. The responsibility for the calculation lies with the builder, since he makes the decisions.

That is logical to us as well. We bear the risk ourselves. We never had the ulterior motive here to put the responsibility on the architect or someone else. Of course it would be desirable if the calculation at least turns out reasonably well so that you know where you stand. But here as well: no guarantees.

We have never had the ulterior motive to hold the architect or anyone else responsible here. Of course, it would be desirable if the calculation at least somewhat matches reality, so you know where you stand. But again: no guarantees.

That’s how it is. I personally experienced the architect of the acquaintance I named and found him to be friendly. I don’t know the real background, which is complex anyway, especially in the family context, but it is clear that they stayed far behind the originally shown plan and still have a half-finished construction site. As already mentioned here, it’s purely a matter of personality whether you perceive this as a defeat or handle it optimistically. Thus, the statements here, for or against, have no deeper significance, as it entirely depends on you how you will or can deal with what lies ahead. You certainly wouldn’t be the first whose solid life suddenly ends in a "family drama" with separation, etc., where neither side really recovers afterward—but equally not the first who find their true life fulfillment in it. By nature, I’m more of a gambler, so I have always been willing to take risks. Accordingly, I also know what it looks like further down, and from this terrible experience, I would be willing to put my now regained standard of living (and by that I mean not unnecessary frills, but a financially untroubled life) at risk for a, let’s say plainly put, 50/50 chance; in my opinion, this chance ratio could be achieved better in other ways. You apparently have never done this or something similar before, and you don’t know the feeling of living on a never-ending construction site with limited comfort and simultaneous financial pressure that can no longer be changed due to the situation (sale), even though circumstances around you may have changed (children, family, spouse, decline in performance). People who do these things often have similar experiences and can assess themselves and their companions better based on experience. I can appreciate a passion project a lot. But I would let it run through my emotional world very thoroughly and seriously in such a life-changing project before deciding. It’s no coincidence they say you shouldn’t throw good money after bad or something like that. I have no intention of dissuading you from what your "dream" or your shared desired life project is. However, if you, like me, are ordinary building owners with fundamentally great interest in self-building and willingness to learn, I would look very closely at the worst case because such interest can easily vanish when it’s no longer a hobby but "survival" (big quotation marks). I always wanted to have a pub or a café. Then I did that for a year and now smile every time my wife suggests whether we should open a café. I once advised a young friend to first tackle a small, manageable project to test himself and as a couple also in terms of perseverance and sacrifice before investing over 1 million in something similar. He doesn’t want to take my advice seriously—well, I hope for the best for him! Finally: you won’t die from this, so the risk is limited to some extent, but it can bring great joy or great, long suffering. It would be nice and helpful for others if you would continue to share updates here, whatever the outcome will be.

The core question for us was above all the financial feasibility. This is still not conclusively answered

No one here can do that either. Especially since the house is not known. Most here are not architects *ahem, possibly bankers and interested laypeople who have some knowledge, a lot of general education and/or experience. Unfortunately, those who are currently renovating themselves are not reading the thread here comes to mind, for example.

You can tell that there are many different opinions here and the "critics" do not have unjustified criticism.

In short: I am also a critic. But I try to read between the lines. And it just can’t all happen on the level of reason. You must have already thought about whether you can manage it. If the only question is about the calculation... that can also go badly wrong with a turnkey house.

I always wanted to have a pub or a café.

Who doesn’t?!

Underfloor heating is one of the most overrated achievements in residential construction. I don’t have it anymore and haven’t missed it a single day. In a historic house, there are wonderful other ways to bring warmth into the rooms without having to accept a massive stylistic break in the floor covering.

That’s exactly how I see it too, and this applies not only to historic houses.
I don’t want to argue against a technology or a decision often perceived as standard today (underfloor heating, heat pumps, etc.), but as soon as you seriously explore options beyond the usual suspects and keep an open mind, you suddenly find alternatives you hadn’t considered before, because currently, for example, underfloor heating is almost the only option in new residential buildings.
Especially in a historic house, but even in our ordinary new build, I would never have wanted to give up our thick castle floorboards, just as little as very large windows, a gallery, or a fireplace, and so we tried to align the other necessary things with those priorities.
I remember a time when underfloor heating was still a luxury and was advertised with the warm feet it provided, until at the same time the aspect arose that floor warmth was not good for the veins. I don’t know if this was scientifically proven, but from conversations, I know that this was often a reason against underfloor heating, this modern stuff.
This will also pass, and who knows what will come then. If I had had different parameters, underfloor heating would also have been installed in our house, but I simply don’t see it as a must-have, as if there were no other options at all. Also, I don’t like all aspects of our heating choice, but especially the type of that feel-good warmth from the fireplace and the atmosphere of the fire; due to the optimal insulation of the house, the need for heating is also limited.
Is it the most sensible or are there more efficient solutions? Maybe, but in a residential building for us, that is not the only driving question, and it is so cozy, and that’s what matters to us in the living space. A motorcycle is completely useless, just like a convertible, an expensive hi-fi system, and most cars anyway. But – it brings joy, and why should it be different inside the house?