Feasibility financing new construction (land + semi-detached house or semi-detached half)

That already sounds very ambitious, but on the other hand, the house will probably be worth 200-300k more right after completion than you paid for it. So if it does get too tight, you’ll be able to get rid of the house quite easily. Is it sensible? Probably not. But you might also regret it if you don’t do it. More personal effort is probably not possible with three children, right?

Now also with a white bathtub, kitchen, and a 25k discount. Almost as if the home builder has to compete for customers with discounts. Too good to be true. I leave it to others to dissect Allkauf Haus in detail.

But I can guarantee you that you won’t know the true price tomorrow. You can’t know it either. With these promises, the construction service description must have major gaps, and you won’t recognize them as a beginner. A first indication of this is the "Ausbauhaus" in the domain name. The target group is not people who just want to move into their finished house (do-it-yourself with 3 small children...) but those who want a tight shell construction.
Just don’t sign anything hastily because of any time-limited promotions.

How large is the property, just out of interest?

I would be a bit cautious with general contractors like Allkauf Haus. I could be mistaken, but I once watched quite a few construction defect documentaries on YT and recall that they showed up there quite often. Of course, this can vary regionally, but in general, the construction price for the Stuttgart area also seems very cheap to me.
For you, purely from a household service perspective, it's really a tight squeeze. With that loan amount, we would prefer not to have a 5 in front based on gut feeling (still undecided), but we have significantly higher incomes.

If I were you, I would fire up interest calculators, there are good ones online. With very high loan amounts, you also quickly run into the problem that the loans would run very long at 2% amortization. Well, you are still quite a bit younger than us, but the interest rate uncertainty then comes on top for a follow-up financing with presumably high remaining debt.
Because of the interest rate development this year, I am also a bit worried, but it cannot be predicted exactly how things will continue. I have also read sound arguments suggesting that the development could relax somewhat. Still, a general upward trend can be seen, even before the war.
Would it be important for you to have the house paid off around retirement? You could try calculating different interest scenarios and see how long you would need.

Allkauf Haus? Those are shell houses, right? There are additional finishing costs,... all the interior finishing is DIY. Or am I mistaken? The price would then add up: 100,000€ in EL... is that manageable?

Good morning, besides the house price which is still vacant, the current project is already very, very tight. It is unfortunately a league too high for you. Stay away, don’t make yourselves unhappy. There is already a reason why construction projects in and around Stuttgart are so expensive. Or why should you get a bargain house?

We all roughly have the same financial circumstances. If we had €1,500 gross more per year or equity over €120,000, we would be excluded, as the city has predefined exclusion criteria for income and capital in the allocation process.

You don’t know that. The same regulation applies in our municipality. I have always wondered how people with this income can buy (subsidized) plots of land at €600-700/sqm. By now I personally know many and definitely know of two parties who received six-figure sums from their parents AFTER the purchase. That is the difference then.

On the topic of reselling immediately again. In our municipality, you have to live there for 15 years, otherwise you have to pay the difference to the standard land value as a penalty. That can also end badly.

And on the last topic of building together with the same provider. In our development area there are many semi-detached houses and most halves were sold individually. But only a few managed to build together. For example, with Al.... I would have been out immediately.