Wiring sockets, switches

1.5mm² for sockets, 2.5mm² for appliances in the kitchen such as stove, oven, refrigerator, etc.

Oven, refrigerator and so on are simply plugged into the socket anyway. The refrigerator also consumes very little! Everything is also protected with 1.5mm² and 16A in my case. However, embedded in the plaster and right next to the distributor, so very short.

Oven, kitchen cabinet and so on. They are simply just plugged into the socket.
Refrigerator also consumes very little!
In my case, everything is also protected with 1.5mm² and 16A.
However, embedded in plaster and right next to the distribution box, so very short.

Well, no one really knows exactly what an individual operates at home.
If you are a fan of nostalgic stove/oven, then quickly more than 3KW can add up (1.6KW oven, 1.6KW stove). Of course, it is rather rare that all 4/6 burners and the oven are operated simultaneously, but I like to lay 2.5mm² in the kitchen for these devices.
“Open-plan kitchens” also often have a fondue, deep fryer, etc... coffee makers and kettles should not be overlooked either. That’s why there are several branch lines for sockets. Do you know what’s coming tomorrow?
And the costs really remain within limits....

Well, no one really knows exactly what an individual sets up at home.

Basically correct.
Of course, circuit breakers should never be designed according to the device but according to the wiring (including length and installation method).

I just wanted to say that it makes no sense to use 1.5mm² everywhere but then specifically 2.5mm² for the refrigerator.

If you are a fan of nostalgic stove/oven, you can quickly get over 3KW together (1.6KW oven, 1.6KW stove).
Of course, it is rather rare that all 4/6 burners and the oven are on at the same time, but I like to use 2.5mm² wiring in the kitchen for these appliances.

My oven alone already has 3600W and is not nostalgic. ;)

“Open-plan kitchens” also often have a fondue, deep fryer, etc... plus coffee machine and kettle

And do you have all of that on at the same time?
If everything is done according to regulations, the breaker will trip if you actually have too much running at once.
But with a fondue or deep fryer, you almost certainly won’t manage that. ;)

we did that with us because later no one knows if maybe the refrigerator ends up in the oven socket after a kitchen renovation ;-)
With us, extremely short distances from the distribution board to the consumers, so negligible from a cost perspective

By the way, our electric fondue has 1100 watts, the raclette 1400 watts. Nevertheless, the RCD tripped on Christmas Eve because the former was defective. Fortunately, there was a spare next door :p

My oven alone already has 3600W and is not nostalgic. ;)

Well, it doesn’t have to be nostalgic, that’s why I wrote that no one knows exactly who will operate what. That’s why 2.5mm²
Fridge of course not - logical

And do you have all that on at the same time?
If everything is done according to regulations, the fuse will blow if you still have too much on at the same time.
But with a fondue or deep fryer, you almost certainly won’t manage that. ;)

Well, if the fuse blows then, you haven’t gained anything either, because you do want to use the devices, which is why again here = 2.5mm²
Air fryer can easily have 2KW, fondue also about 1.4-1.5KW... And there are surely even more power-hungry ones, similar to your oven...
Be that as it may....

Oversizing pipes can be done by anyone as they please. One should only differentiate between fun, sense, and regulation. Although, actually you don’t have to do that yourself, because there are professionals for that.