Stress-free building - Who has tips or experiences on how to do it?

That only makes sense if A) you can work almost unlimited hours in your job and get paid accordingly. And B) the net hourly wage exceeds the gross wage of a "skilled worker".

No. You imply that the skilled worker needs exactly as long for his work as a DIY builder. But that is not the case. I would factor the DIY factor at least with 2, rather 3. Goodies like warranty, synergy effects, and volume-related material quantity discounts are not yet considered.

No. You imply that the skilled worker takes just as long to do the work as a DIY builder. But that is not the case. I would estimate the DIY factor at least as 2, rather 3. Benefits like warranty, synergy effects, and volume-related material discounts have not yet been considered.

That's why in 90% of jobs there is only a certain number of hours X which determines a certain salary Y. Therefore, the argument "I'd rather work a job for that" is actually not tenable. You just sacrifice free time/vacation for the project and maybe take a little longer than the skilled worker, but you don't pay for labor hours.

One should also compare how much labor costs and how much material costs are. For a painter, it is certainly the case that labor costs have a relatively high share. But anyone who has watched how quickly a painter/plasterer fills and sands drywall, and how long it takes oneself, sees a factor of 4 difference. For heating, electrical work, and also plumbing, labor costs are often just 15-20%. How one wants to save, say, €120,000 on a house construction costing €350,000, I don't understand. Where else besides labor costs can one save? Most materials are purchased by oneself more expensively than by the craftsman plus his handling fee. Please don't get me wrong, anyone who works themselves can doubtlessly save quite a lot of money, but in my opinion, many things are sugarcoated here. Just thinking about how much my tools cost, I am quickly in the mid four-figure range. Maybe I am just too slow/bad.

No. You imply that the skilled worker needs exactly as long for his work as a DIY builder. But that is not the case. I would apply the DIY factor at least as 2, rather 3. Goodies like warranty, synergies and volume-related material quantity discounts not yet considered.

I'll say it again: I'm not talking about skilled worker activities. It is often about auxiliary activities like handing over stones, fetching+cleaning tools, mixing concrete/adhesive, shoveling sand, carrying heavy things from A to B...

Of course, it also involves activities like installing compression felt insulation or insulating the floor with Styrofoam, but you don't need to apply a factor of 2 or even 3 there. Those are simple tasks; a factor of 1.2 would suffice.

In the end, I built a house for €240,000, which the architect estimated at €360,000 (even with much simpler equipment).

160 m² living space, 80 m² attic (floor area) not yet developed, no basement, 50 m² double garage (solid), geothermal heat pump, underfloor heating, central controlled residential ventilation, ground floor + bathroom tiled (tile price €60 per m²), upper floor vinyl glued, electric roller shutters, sanitary fittings from Hansgrohe, complete lighting with LED spots, landing staircase covered with natural stone, exterior facade approx. 70% fine scratch plaster + approx. 30% natural rubble stone, Schüco windows, lift-and-slide door...

I am writing this only so that other numbers are provided here in the forum as well, instead of only the opinion that nothing is possible under € 2,000 per m².

I agree with haydee, markus2703, and 86bibo and am willing to pay those who have learned their trade.

We are building with an architect and working with regional construction companies and regional craftsmen who have a reputation to lose. Whether it will be more or less stressful, I cannot say since we are just starting. But even after that, I won’t be able to say anything because I have only had this one experience. It always depends on where one's own stress level is; with a 40-hour week plus a child, it could certainly be more stressful than with 30 hours and no child.
Could but does not have to!
Everyone has to find a way for themselves to organize everything so that it is doable. Bringing friends or relatives to help with the construction site is also not for me... they should also enjoy their free time. A house is important but should not become the center of life, there are more important things in life for me.

I think the performance you and your partner have delivered is great. Longer construction time also means longer rental payments, which can sometimes become a double burden. Loan repayment + rent. You have to be able to handle that too. Possibly loss of earnings because of no more overtime or even reduction of hours. Unfortunately, many relationships fail due to too much own effort or poor financing. I also think these are the two points that make building really stressful. With own effort, you have to be clear that there is no vacation, no free time, and it requires craftsmanship. How many people already need an electrician just to change a light bulb.