Settlement house 1954 - complete renovation possible?

Now a TE is calculating generously here again and it is being spoken of negatively again. I consider it to be sensibly calculated. Because some things will no longer be done in EL when you see the effort involved.
It is true that the exterior insulation on the rafters is more expensive and the roofing may now be unnecessary. But: the exterior insulation on the rafters does not take away living space and is significantly better at heat protection. If it is going to be done anyway, you can also reroof. In this process, the roof overhang can be adjusted for the wall insulation. It can't get any better than that, and you will really have peace forever. It also positively influences the possible resale.

Heat pumps are, of course, also a topic of their own. I find installing underfloor heating very sensible. The heat generator is initially irrelevant there. But the heat pump is always possible.
I would never switch to pellets. You need storage capacity, have to clean, there are more frequent malfunctions. Then possibly a large buffer tank, and the chimney sweep comes frequently.
However, the heat pump also offers a subsidy. And it makes sense together with photovoltaics.
Plan the facade together with the windows. That way thermal bridges can be avoided.

But this was not what it was about here. It was only about the fundamental feasibility, also in financial terms. And I consider that to be given. I even consider it to be sensible and cheaper than a new build.

Calculation is also absolutely fine. Here, he can only save massively without really reducing the feel-good factor.

You can do a lot with a house like this. But you also get 80% of the result for 25% of the cost.

That is the decisive point in a project like this. You just have to think about what you want. If you want everything new and from scratch, then this might be the wrong project.

For the money saved here, the family can have nice vacations over the next 15-20 years.

I have a residential house from the 60s that is also being completely renovated. It's a nice project and I am still in the middle of it.

KFW 430 was a topic for me for a long time, but I had to give up the plan to upgrade it to an efficiency house. That just causes a lot of problems. First, find an energy consultant who dares to take it on, and a lot of calculations have to be done. That costs money again. The cheapest offer was 3,000€ (50% is refunded again through KfW 431). To what extent own work is possible or allowed, I don't even know, it depends on your consultant, and especially then it becomes difficult with proof like the hydraulic balancing.

Probably a basement ceiling insulation has to be installed first and an open stairwell to the basement is also a big problem. The main reason for me against the efficiency house was finally the total budget, because photovoltaics, solar thermal, heat pumps, etc. were simply too expensive. What use is 30% funding if you have 60% more costs.

Besides the 430, there is at least money through the 455 as well.

Make a big buffer. At some point, you notice little things like, for example, an unsightly staircase. Insanely expensive or insanely time-consuming, if you do it yourself. You could also talk about many individual items again; some, like the structural engineer, seem very inexpensive.

Interior finishing has some strange items. 8000 for the breakthrough is 7000 too much.

Could it be due to the statics and a metal beam inside?

Here you simply have to consider what you want. If you want everything new and from left to right, then this might be the wrong project.

For the money saved there, the family can enjoy nice vacations for the next 15-20 years.

I see it the same way: either you like something old trimmed to look new or not.
It would be wrong to dream of a new build and buy an old building.
You have to be the relaxed type for whom the creaking staircase gives a cozy rather than annoying feeling.
I would also skip KfW. Do what is required. They are just numbers.

Make yourself a big buffer. At some point, small things like an unsightly staircase will catch your eye. I

An older house is always somehow "a work in progress" if you do much yourself.

And what is also very important: what feeling does this house evoke in you now when you approach or enter it: Does it give you a home with wonderful possibilities or only the alternative with a lot of work and then well?

We also renovated our REH (if you will, also a settlement house) from 1921. I think you calculated well, here and there even generously, so you can certainly get more craftsmen for the money if you find any. You will probably need them if you want to finish it within a year alongside full-time jobs and children, as you wrote. Which brings me to the next topic: Without knowing the house now... maybe you don’t necessarily have to do all of it. Of course, the question is whether you want to completely overhaul everything to brand new in one go or rather, for example, leave the roof as it is for now (which looks okay to me in the photos, and you can also insulate it from the inside).

We had companies do the following for us: tiling work in 2 bathrooms and the tile backsplash in the kitchen, complete simple electrical installation, new radiators and piping (water, sewage, partially new lines, outdoor water tap, also new lines in the basement), 2 new roof windows, roof interior insulation with drywall cladding. Ceilings, floors (partly new dry screed etc.), walls, drywall, sanding stairs, mostly new windows and doors (except the front door) were done by ourselves. For this, I was on site full-time for 5 months and my husband also worked on holidays, weekends, and during his vacation; we mainly had help on weekends from family and some friends. Altogether, about €60,000 was spent. But everything was done simply (sanitary stuff, electrical, interior doors, good laminate, etc.) and that was in 2017. Not cheap, but also not expensive, simple standard – we could easily do without parquet, KNX, and a washbasin for €800. Since we have wooden beam ceilings, we did not do screed, and I only refurbished the old interior plaster almost everywhere instead of completely renewing it (which I regret today and should have just done completely from the start). The facade and roof were from the 90s and still completely fine, as were the basement door and basement windows. The front door still needs replacement, the basement plinth needs new plastering, which would cost about another €6,000. Here and there some minor stuff, say another €10,000 and we would have been done. From a financial point of view, it often doesn’t make sense to insulate a house to death and install everything newest everywhere, especially since airtight sealing in old buildings tends to cause more problems than improvements. For example, our 8-year-old gas heating was totally fine. Now it’s 10 years old and still runs without problems; our gas costs are €61 per month, electricity €83 for four people. All completely within an affordable range. We could have easily thrown in another €80,000, but that would have been nonsense. Facade and roof will still come eventually, but that might take another 20 years.

We love our old little house, it has character, it has history, it has a healthy building substance (built from bricks combined with some timber framing). We have not regretted it. Through the renovation partly done by ourselves, we really grew together with our house, and I really enjoyed it, although my husband not so much. It was stressful nonetheless, and it was a real sprint that we wouldn’t have lasted 12 months doing... maybe 7, but more rather not.

Conclusion: The location seems good, and if the substance fits, I would buy it, renovate sensibly and thoughtfully, and then you will have a nice little house with character in a well-established location, as the saying goes.

I almost everywhere just repaired the old interior plaster instead of completely renewing it (which I regret today and which would have been better to have done completely from the start)

I removed the old plaster in all living rooms and the kitchen. Walls and ceilings. Today, I rather regret that I completely underestimated the costs of plastering.

Out of consideration for the neighbors, I also had to take time off work for this; on weekends and evenings, it is definitely too loud.