Height of tiled walls in bathroom 1.2m or 1.5m?

maybe one or the other will post a picture

There is a bathroom thread here.

In the guest bathroom I have the problem that the window sill height is at 1.42m top edge of finished floor! That means either tiles up to 1.2m with 22cm plaster between bottom edge of windowsill and top edge of tile. Or tiled up to 1.5m and then no windowsill but a tiled parapet.

I wouldn’t make a doctorate out of it, nor is there a universal height or right and wrong. Look at your bathroom: does it even have to be tiled under the window? What about the other walls? Where does the shower start? What about the wall to the left and right of the window? Overall, there is no either/or rule, in addition taste and style also play a role. It is also no shame to cut tiles in inconspicuous or subordinate areas.

Now we could go to 1.2m (4x30cm) or 1.5m (5x30cm). [...] (Floor-level showers are tiled floor-to-ceiling around the perimeter).

Preliminary remark: I do not see the necessity to decide between 120 and 150 cm - if I wanted 140 cm, I would do that too (i.e. start with a cut row, 20 is after all two-thirds of 30). When weighing only black/white, i.e. 120 or 150, I would prefer five over four rows: then there is a row in the middle of the height, not a grout joint. The floor-to-ceiling tiled showers make me consider whether it would be better for the pattern to start at the ceiling instead of the floor.

Top edge of the finished floor is! That means, either tile at 1.2m with 22cm plaster between the bottom edge of the window sill and the top edge of the tile. Or tiled at 1.5m and then no window sill but tiled parapet.

one decides how

Preliminary remark: I do not see the necessity to decide between 120 and 150 cm - if I wanted 140 cm, I would do that as well (i.e., start with a cut row, 20 are after all two thirds of 30).

Whereas, basically, I am also more a fan of real window sills and then only tile up to the window sill, i.e. 142 cm.

When planning, I am on my own. My wife at most says: yeah, looks good or (when I have already settled for it) no, I want it different. She takes care of other things.

That sounds very familiar to me – especially whenever a topic was abstract or technical.
With the abstract, she was worried about developing a wrong impression and then being disappointed. Therefore, we conducted the planning in such a way that we made many decisions only when the room was already there. With a wooden house with an installation level, that is quite easy. Without the joint coordination, the house would not have become nearly as good for us as it is now.
With the technical, she was worried about the complexity and simply refused to think it through. Therefore, we abstracted the technical details and formulated goals based on that – environmentally friendly, easy operation even in old age, aesthetic standards, impact on our well-being. This way, we had common guidelines within which I could then “play around.”

My tip (warning: expensive!): Build the house and walk through the rooms together to, for example, draw tile options on the walls with chalk. Look at pictures together and pin them up – because you like that… Maybe you will also experience that your wife comes up with brilliant ideas. It works better that way.

Topic windowsill: We have a beautiful yet roughly treated wooden board as a high windowsill. Yes, it is not very durable - it will simply be replaced after a few years. The look is fantastic and the price a handful of euros. Sometimes you can also think about things simply.

Above all, I consider the remark "said that 1.2m would look better" to be nonsense (please do not pass this on to the tiler). The good thing about "taste" is that everyone can have their own. When something "looks good," it is often because one is "used to it that way." I find that a weak criterion. I consider it more important to train your own experience: What do you like? (don't be confused if others prefer it differently)