Electroinstallation too expensive - oversized or too expensive?

Yes, that is precisely one of the problems, normally it goes like this:

- You put 16A circuit breakers in the distribution board
- Lay 3x1.5 or 5x1.5 cables to all the sockets in the house (no matter how far they are or in which medium the cable runs)
- It is measured and everything seems ok

But when a bunch of devices are later connected to the mentioned line, the user has a problem... but he doesn't know about it because he always relies on the 3600 watts...

Without considering losses etc., 1.5mm² and 16A is the limit at 18m... and that is reached faster than you think, especially if the distribution board is in the basement.

That’s why it’s better to have a few more sockets + circuits, then there is still room for expansion...

We also install almost everything with 1.5. But because we also run several cables per room into the cabinet. Only for the dining room and kitchen is there 2.5. However, I cannot think of a case for 16A in the bedrooms...

18 meters is really nothing, he's right, especially if, like us, you have the ventilation under the roof and the distribution opposite in the basement...

We have two UVs and basically no socket batteries nor interconnected wiring except for a few exceptions. I have not laid 2.5mm² anywhere - because it simply was not necessary. Therefore: It always depends, blanket judgments are wrong.

We also lay almost everything with 1.5. But because we also run several cables per room to the cabinet. Only for the dining room and kitchen there is 2.5. However, I can't think of a case for 16A in the bedrooms...

Vacuum cleaner plus a few other consumers, such as waterbed heating, etc.

no 2000 watt sound system