Floor plan of bungalow with hip/gable roof, 130 sqm

since it’s not much and won’t really increase significantly.

Of course it will increase. This has nothing to do with the house, but rather with the fact that in life you sometimes buy something but don’t throw anything away.
At 40 years old, you will own more than at 25 years old.
But whatever: You have been warned. What you make of it is up to you.
Regarding the costs: there are plenty of info threads here that you can use as a guide. It’s not like we want to harm anyone by saying that the calculation is too shaky.

so we have an 8.4m² kitchen in our rental apartment with a 1.5m² pantry directly attached, in the basement only one kitchen item is stored: the raclette grill. everything else fits in the kitchen or pantry, the grill would also still fit there (the washing machine is also in the pantry). it is possible, but the idea of having only this limited 10m² space my whole life (that is the hope when building a house) would not be for me, I am not building for a lot of money for that....

First of all, the floor plan is not bad. Only since the technology still has to go into the utility room, that is the boiler and the electrical cabinet and so on, it is actually too tight. To also serve the utility room. The kitchen is big enough, ours is like that too. But we have the utility room directly next to the kitchen and in it washing machine and dryer and coat closet and pantry and a second sink. In addition to the technology. So, please reconsider this. The BU will advise you on how to do it better. Anyone building without a basement has to think about where to put the things that you simply don’t want in the kitchen, living room or bedroom. For us, these would be suitcases, winter jackets, tools, garden stuff etc. pp. As a man you need a place to tinker, the children’s bikes have to be stored, etc. Do there really have to be two cars, two galvanized and painted and otherwise protected metal bodies inside? Isn’t that a waste of space and money and just a habit from the late 50s, when dad loved his Beetle more and washed it more often than the children were bathed. K.

As a man, you need a place to rummage,

Nordlys... KARSTEN... shame on you
You can surely do that on the toilet too, if it has to be!

So, we are now at the point where we will definitely change the floor plan in this regard: The bathroom will be reduced by 70 cm so that the utility room can be enlarged by this amount. Then there should be enough space in the utility room for the washing machine and dryer. The guest bathroom will remain as it is for now, but it will have a closed shower because otherwise it doesn't work. The kitchen as well as the living-dining room will remain as they are. Due to the open ceiling, it should not feel too cramped.

In case anyone is still interested, here is now our final floor plan.