Financing plan too unrealistic?

What is 'begeschwistert'? And what is an intermediate house? Wouldn't it be more sensible to keep renting...?

I think means another planned but not yet existing sibling :)

and an intermediate house as an alternative to the price-uncertain new build, e.g. a terraced house or semi-detached house from the developer (fixed price, house and land together) or an existing house.

Which can then be sold at a later time, when the conditions are right, for the then possible new build..

What is begeschwistert? And what is an Zwischenhaus? It would make more sense to stay renting...?

has just given my answers. By the way, one could definitely also rent an Zwischenhaus.

Personally, that would be way too tight for me. If additional costs arise, you quickly end up with a rate of 2,000 EUR. Parental allowance for the second child will definitely be lower in any case.

For comparison:
We currently have 5,600 - 5,800 EUR available for four of us and a rate of 1,200 EUR.
We manage very well with that and can easily cover unplanned expenses, such as unfortunately currently around 3,400 EUR for our cat (emergency operation, veterinary clinic, follow-up treatment) or dental prosthetics for my wife (still to come during the year). That naturally hurts us, but the world doesn’t end because of it and we don’t need an additional loan.

We are also still in the fortunate situation of having a very cheap electricity and gas tariff (for gas currently about 4 cents kWh). But that will certainly change over the course of the year. That is annoying, but the additional costs of about 200 EUR per month do not drive us to despair.

With a planned second child and another baby on parental leave, the future division of family work is still a wildcard, which can mean part-time for years.

Well, if you look at it that way, you probably should never build without completed family planning. You can see it that way, but it is usually also the time when the desire for something of your own grows the most. With his current salary of 3.8k net plus the bonus, I still see better conditions here than many who dare to do it anyway. (Even if she were part-time for longer. Which is not the case for everyone) Maybe I am just too positive :) (By the way, I still think it’s really good that many of the warning voices speak up here. It also provides incentives to look at things from several perspectives, even if I sometimes see it differently)

If the costs work out this way, my impression is you can do it. My question mark is more like, do the construction costs really add up like that.

and a mid-terrace house as an alternative to the price-uncertain new build, e.g. a terraced house or semi-detached house from the developer

P.S.: a mid-terrace house can also definitely be self-built, for example as a plastered Flair instead of immediately the clinkered Maxime or Jette. The type of house and financing chosen depends individually on the family constellation; in this case (K1 very small, K2 still uncertain if and when, building couple in their mid and early 30s), self-building or buying as first-time buyers can fit well; in other constellations, renting is better, or or or ...

I only see an intermediate house option if you don't irrevocably sink too much money into additional costs. An existing property for 400k is definitely out, because the 50k for ancillary purchase costs are missing afterwards. Building is also questionable, as you probably won't be able to free up decisive amounts by building a Flair 113. Because the missing items in the current calculation still apply there (kitchen, higher secondary construction costs, outdoor facilities). And in many new development areas, as a property owner you are basically excluded from the allocation process.