House construction: Dream of a house affordable?

How are you doing age-wise? Do you still have enough time until retirement?

I will turn 35 this year and my wife will be 32.

Overall, already a considerable burden with relatively low repayment. I also believe that the house costs are underestimated. Additionally, with the basement, slope, etc., surprises are possible that cause further costs.

I find that a very tight story, especially the costs should continue to rise. For example, we always calculate here with €2000/m² or the double garage for €25,000. There will definitely be more added to that. With more children, the salary will stay at €4000 for the next few years.

So and now you are asked...is that doable?

Difficult. Personally, I would take the risk, but only because vacations, cars, or other consumer goods are not important to me personally.

Did you save the equity yourself?

To be honest, I don't find that SO tight at all, provided the numbers add up. If you subtract your equity, you have a loan amount of about 400k, you are young and by the time you start repaying, child 1 will definitely be just about to start or already in kindergarten and your wife can work part-time.

3,200 + 1,300 + 200 = 4,700 euros.
From that, you can repay 400k, even within a reasonable time (30 years would be perfectly fine).

You can always calculate positively, or you can turn the tables and say that there will be another gap before the child starts kindergarten. Elterngeld Plus will only be paid out for 1.5 more years, but the child usually comes into care at the age of three, possibly even later if the kindergarten has unfavorable regulations here (which, by the way, also costs money).

In addition, there should first be a concrete offer to see if the costs fit, I am of the opinion that this is calculated very cheaply.

Even if there were still a gap of half a year, the OP said 1,200 would be feasible with the current 4,000. The "problem" is more the house itself, but you have to set a clear maximum budget and then calculate realistically.