Experiences with construction cost savings through self-performance?

You have to finance the entire construction with construction financing, meaning the house "ready for occupancy." Financing the delta between a shell house and a ready-for-occupancy house outside of construction financing with a consumer loan is practically unmanageable.

how do you come up with consumer loan? Between technically finished as an example and turnkey (without kitchen) there is a 40k difference. This includes not only material costs but also labor costs. If we now assume 1/3 material costs, we are at 15-20k. These are then financed from equity, which is not included in the financing.

What kind of professional background do you actually have? Ever done anything manual or even learned it?

It's important to set realistic goals and not plan 70 hours of personal work per week for 6 weeks of annual vacation. That simply won't work.

No craft profession. Actually did 2 years of apprenticeship as an electronics technician. I still have some knowledge from that and can also pull cables, chisel slots, install sockets, and understand how circuits work. But that brings me less here.
However, I know how hard work on construction sites is and can handle materials.
Otherwise wallpapering, painting, laying laminate, assembling kitchens, grouting showers, building wardrobes or built-in closets, etc.

So smaller tasks to at least maintain the house.

Also tinkering with the motorhome, soldering, or other things is not foreign to me.

And otherwise, there’s forums and YouTube. Honestly, there is really a lot of content where you can learn many things.

how do you come up with consumer credit?

Because you spoke of this budget share as if it were not part of the construction project financing in your planning. That made me assume borrowed money financed from outside the construction funds, i.e. a consumer loan like for kitchen / washing machine / TV / car & co. – but apparently you plan it differently again: ...

Between technically finished as an example and turnkey (without kitchen) there is a difference of 40k. This includes not only the material costs but also the labor costs. If we now assume 1/3 material costs, we are at 15-20k. These are then financed from equity, which is not included in the financing.

... namely from equity, which you exclude from the construction financing. Well, from the loan volume, that might be calculated sensibly. However, in the financing planning, it should not be just as "invisible." But factually, these are construction costs, and they also become part of the house as real collateral for the borrowed construction money. So it is unwise to leave these positions out of the construction financing planning.

Especially since it is not significantly cheaper to include the material and tools for the own contributions at 3.5% in the mortgage over 15, 20 years, instead of at 5% in a private loan over 5, 6 years. But it does significantly reduce the burdens from the installments at the beginning, when money is usually tightest. I read that [auch noch Kinder geplant sind], just wait and see what other costs will come your way...

Hello Papo,

I have now been working on "my own work" for over a year. It is a marathon, not a sprint; with many topics, before the construction started, one quickly said "yes, I'll do it myself"... but in the end so many tasks come up that you didn’t even have on your radar at that time.
If you have a family and a job and spend almost every evening after work and every Saturday all day on the construction site for over a year, that is certainly not easy, one really has to be aware of that.
The initial enthusiasm and eagerness could be maintained for a long time, but it definitely diminishes after a few months and some setbacks (which will certainly come).

I just want to say: think everything through carefully and be sure how much time you can really invest each week without neglecting other things.
You definitely save money, but how much are evenings with family etc. worth?
I don’t regret it and am proud of the many things I did myself, but I am also happy when you finally move in and some normality returns.

Best regards

You definitely save money, but how much are evenings with family, etc. worth?

The question really doesn’t even arise in that form.
Either you do the work yourself because you enjoy it and/or you can’t or don’t want to afford to hire companies.
Or you can afford it and have it done...

There are few shades of gray in between.

For me, it was clear from the start that I had to do most of it myself, because otherwise owning a home wouldn’t have been possible.
If we had everything done, we would have to turn every cent three times over by now, and that can’t be fulfilling either...