Financial planning for new construction with good income and little equity

We have a daughter. I work 39 hours a week. There is still enough time left for personal effort. If craftsmen were here, I discussed it with them beforehand, took time off, and worked along. By the way, I only had those with an hourly wage. Friday afternoon, Saturday, Sunday—all working time. Either you want to achieve a goal or you don't.

According to the construction service description

Oh yes, you have that. Then I don’t need to scrutinize the exposé and speculate. …..

But whoever is diligent and intelligent and rolls up their sleeves for 3 years

Maybe he isn’t?!

The key is education, willingness to take risks, and physical fitness.

Maybe he doesn’t?! Don’t get me wrong: I think that’s very good and I respect such decisions as well as perseverance. Everyone has to manage on their own, and before you complain, you should have a plan. But everyone who is different and does it differently than you is stupid in your eyes. But isn’t it rather stupid to flaunt your supposed diligence boastfully everywhere, even where it’s not the topic and you’re not asked? That’s just embarrassing. Isn’t it smarter to let people work and be able to pay for everything with your salary? To live your life the way you want, without crawling around on construction sites?

Either you want to achieve a goal or you don’t.

That is basically correct.
But not everyone has the same conditions. For example, I can’t take vacation whenever it fits with the craftsmen; rather, the craftsmen have to fit the vacation schedule. And with 39 hours/week and free weekends, it doesn’t work for me either.
I’m quite handy and do myself what I can. But not everything is possible, and it doesn’t start to work just because you want it enough—that was the point.
Also, I would never waive a warranty on certain trades just to do it myself. And I don’t want to live on or with a construction site for years.

But yes, it’s true: then it’s more expensive than if you do everything yourself in the time it takes. Our solution for the cost aspect was: smaller is also good. We had the bathroom and the installation of new roof windows done, but retrofitting smart home (wireless), partially painting, and the entire garden and landscaping work we did ourselves (or are currently doing in the garden).

That is a significantly more realistic because average affordable specification than what you need to (allegedly) halve the price per square meter.

We have a daughter. I work 39 hours a week. There's still plenty of time for personal effort. When craftsmen were there, I had agreed with them in advance, took time off and worked along. By the way, I only had those with an hourly wage. Friday afternoon, Saturday, Sunday were all working hours. Either you want to achieve a goal or you don't.

Could be anything – but such a project always comes at the expense of SOMETHING.

Either at the expense of family, partnership, or ultimately at the expense of one's own health (both physical and mental).

Honestly, I wouldn't want to live apart for 3 years and not be able to give my family what I would actually want to.

Everyone is different in this regard – you definitely shouldn't generalize...

This has absolutely nothing to do with rolling up your sleeves.

My wife would have honestly flipped out if I had come up with such a project idea...

Plus, of course, there's also the craftsmanship skill... Some just can't do it.