Suitable floor plans for all our requirements

Always this children's room discussion.

I used to have 9 sqm and I'm still alive. My children have 12 sqm and they will survive it too.

Of course, 15, 18, or 25 sqm are great. But even with 9 sqm no child gets harmed.

In social housing, a children's room must be at least 10 sqm (although it is not defined how many children may live in it).

Now to the costs:
I don't really believe your calculation. You can assume 10% incidental building costs for a construction project of 400k or more, but not for your savings program. The rest is also very optimistic for outdoor facilities and garden, etc. In the end, you will probably have to add significantly more.

But there are other experts here who can break it down better for you. Somehow I see at least a 3, maybe even a 4 at the front of the room plan including the plot. And I know what our house cost three years ago.

Again and again this children's room discussion.

I used to have 9 sqm and I'm still alive. My children have 12 sqm and will survive it too.

Of course, 15, 18, or 25 sqm are great. But even with 9 sqm no child will suffer damage.

In social housing, a children's room must be at least 10 sqm (although it is not defined how many children are allowed to live in it).

I also grew up in 9 sqm and was very happy about my 12 sqm later on. Now with my son, I have a different perspective again. He has just under 12 sqm and it's quite elongated. I find that sufficient. The other children’s room is squarer with just under 11 sqm. That is significantly harder to furnish sensibly. 10 sqm and square. Good luck! The bed is right at the head end and after two steps you already reach the closet. In one corner you can still squeeze in a small cabinet for the TV. Yes, it all works. But if I build a 240k house, then I should come up with a really coherent concept. Do I need 4 children's rooms at 10 sqm each or is a shared bedroom for sleeping enough and a larger one for playing? That’s how we will do it, as long as the children accept it. If I plan at least 3 children and only have the budget available, I should consider alternatives.

[emoji33] I am reading something about 4 children's rooms...

[emoji33] I read something about 4 children's rooms...

3 are mandatory. 4 would be nice.

Somewhere there was already talk of about 40 overnight guests per year.

And, the last examples did not exactly have large utility/technical rooms. They offer hardly any storage space; even a washing machine/dryer can already be difficult there.

The whole floor plan planning is an academic matter without a plot of land.

That's right, even if the (preferred) building area is already "fixed". There can not only be very different layouts even with otherwise identical plots, but nowadays new building areas are often structured: in one section detached houses with one full floor and in another semi-detached houses with two full floors, for example. Or precisely the part where you would most like to have your plot goes to a developer (who then lets you "choose": kitchen with or without a wall to the living room, carport or garage).

But on the other hand: that does not mean you shouldn’t consciously engage with floor plan planning already. All beginnings are hard, and in the end, you can become skilled at realizing that you might need to look for your suitable plot in a different building area. Others have also initially gone through a phase of mistakes and confusion – the main thing is that in the end there is a fitting house.