Which task is worthwhile to do yourself?

... then fingers crossed that everyone keeps their appointments, because the trades are quite interlinked. Only if that goes well can you speak of a successful individual awarding.

Well, I have now accompanied two construction sites with my brother-in-law and a good friend quite intensively as a helper. All in individual awarding and moving in after 11 and 12 months of construction time. I think we can manage that too.

Yeah, that works, don't worry about it. We took 10 months with individual awards and were often delayed. So there's definitely a good buffer in there

and if not, this apartment belongs to us

But again, I also understand if I do not award single contracts when I live 100km or even further away (I live 200m). Only "laziness" is not an argument for me, but everyone has to decide that for themselves. The general contractor, architect, or whoever is doing the construction supervision, for me, to get back to the topic, has the greatest potential for savings in the entire construction.

and if not, this apartment belongs to us

But again, I understand if I don’t do individual contract awarding when I live 100km or even further away (I live 200m away). For me, "laziness" is not an argument, but everyone has to decide that for themselves. The general contractor, architect, or whoever is doing the construction supervision has, for me, returning to the topic, the greatest saving potential of the entire build.

In my opinion, the decision whether to build with a general contractor, architect LPH 1-9, or architect up to execution planning is a very large cost factor.

I also agree with my predecessors that it strongly depends on the region and makes a difference whether you build in urban areas or in the countryside. In the countryside (at least in our area), there is still trust in good craft businesses.

Back to the actual topic:

Everything that can be done with average craftsmanship has already been said here.

However, if you have friends/acquaintances or even relatives in technical building equipment, I also see a lot of self-effort and thus saving potential here.

In my opinion, the decision whether to build with a general contractor, an architect for phases 1-9, or an architect up to the execution planning stage is a very significant cost factor.

I also agree with my predecessors that it strongly depends on the region and makes a difference whether you build in urban areas or in the countryside. In the countryside (at least in our area), there is still trust in the good craft businesses.

Back to the actual topic:

Everything that can be done with average craftsmanship has already been said here.

However, if you have friends, acquaintances, or even relatives in technical building equipment, I see a lot of potential for self-contribution and thus savings.

Yes, as long as they are willing to sacrifice their free time! The times when neighbors built illegal structures are over. Now even the masons are already crying out for a sabbatical.

You can't set guidelines for which personal work is manageable. Everyone is different, with different job conditions, routes to the house, family situations, circles of friends...

Friends of mine recently built a house. They more or less just had the shell done by a company; for the rest, the friends were gathered together. That worked great, on the one hand, many "experts" in the friend circle could give good instructions, on the other hand, the workdays ended with a barbecue party. The roof party was legendary. 12 people, a few hours of work, 12 kilos of meat, and 12 crates of beer.

Others built farther away and actually wanted to do the floors, the attic conversion, the room doors, and the painting themselves. In the end, a company was hurriedly hired for the floors; the painting was initially reduced to the most important rooms, and the doors were installed only after moving in. The attic is still unfinished after more than 10 years. The time required was simply completely underestimated. From "we'll paint on the weekend" it first turned into a long breakfast to gather strength, then a visit to the hardware store to get everything; while there, you might as well get this and that and that. In the afternoon then arrival at the house. And the surprise that you should tape off first. So back to the hardware store ^^ Nothing was painted that weekend.

We are remodeling and doing everything ourselves. However, we are not under such time pressure. Currently, we want to plaster two walls of bricked-up doors inside—but that won’t happen because the sand outside is frozen. So we wait. Meanwhile, we already start the next thing. We are making good progress. But that only works because we live in the house, so we can also quickly do something in between; my partner is self-employed, I work part-time plus a small self-employed job where I can schedule projects freely. But if a certain task had to be finished by a certain date because the next trade is waiting, that certainly wouldn't work. Something always comes up. And even if it’s "only" a bad cold, a strain, or a lumbago.