Building financing - Is the income in order?

The flat rate for household expenses for two adults with a child is about 1,100 euros.

That (perhaps also the 1,400€ flat rate) matches an income as a flat rate. The problem is that the original poster has aligned his standard of living to 5,000€ for years - including fixed commitments. That won't work well in the long run. It is clear that parental leave is not a problem. With my three kids, we always planned for three years. The kids are worth that...

The area of the plot is 660 m2 and the house has a living area of 144 m2. And the plot is relatively very affordable. We live very frugally and save about 2500-3000 euros per month. Therefore, I think it will be doable. Thank you very much for your information.