Pretext in the bathroom on the upper floor directly next to the window

The alternative is not "there or not at all." You can also lay the cables in right away or find another location.

Maybe the construction company will also "forget" it. Just like my 3 KG pipes, which my house seller recommended for a later heat pump. They simply don't exist now.

I would be more concerned about how the tiles behave that possibly go around the corner into the window area. Then I would rather carry the thing all the way to the window reveal to have a flat surface and not constantly have to patch up.

The enclosure of the conduit is drawn about 3 cm recessed behind the reveal. This fits if an interior windowsill is planned there and the reveal is not tiled. However, I would rather tile the reveal as high as the surrounding wall, and instead of an interior windowsill use tiles here as well. This then fits more neatly with the shelf, which will presumably close off the installation wall for the washbasins at the top (and which, in my opinion, should already be drawn in the floor plans at this level of detail).

And apart from tiles etc., wouldn’t it look silly if the window is so boxed in by these enclosures when they are extended up to the reveal? That is probably another 15-20 cm in front of the normal wall...

It's a matter of technique and dimension. We have planned a 100mm conduit for photovoltaics, and it shouldn't be much less than that. With a 40mm one, we wouldn't stand a chance.

Unless you’re putting 300 kWp on the roof, that’s not true. The cables for my 10 kWp would have also fit through a 20mm conduit. With a line that fills a 100mm diameter, you can supply a small town with electricity.

You mean the wall with the sinks now? I guess there will be a pre-wall installation if needed for water and sewage. It is not drawn in now

Sorry not quite clear, I meant that it is exactly the same with the sinks. I also think it looks strange.

If you’re not just slapping 300 kWp on the roof, that’s not true.

You’re probably only thinking of the usual photovoltaic panels. With photovoltaic solar tiles, you have more parallel operation and therefore more cables, which in turn requires more space. If you prepare something, you can definitely do it with a view to tomorrow’s solutions and not today’s or yesterday’s – hence my comment.