The same tiles throughout the entire ground floor and in the bathroom - also the same in the basement?

Tiles are, after all, hard, cold, and expensive.

In the basement, we also have underfloor heating everywhere. So not quite cold, the tiles. Expensive and hard, of course, is true. I calculate at least €110/m² (material, labor...).

How do you have it?

Same coverings within the floors, "softer" on the upper floor than the ground floor. In the sleeping area, I only find tiles good in Mediterranean countries.

but it depends on the overall design of the house.

Yes, but a basement where you can't directly look in from above due to lack of daylight could also use something simpler.

Tiles cost around €35 net/m² for the material price.

At that price I wouldn't hesitate. Although net, about 10 years ago we saw prices of €18-25 for basement tiles (we had considered something cheaper than €70 main tile for our utility room), so I don't find the €35 plus tax overpriced. Then the basement is matched and you won't regret it later.

We have planned tiles throughout the entire ground floor of our new build, similar to those in the attached photo. They are called Kermos Stoneline natural beige 30x60. We have also planned to use them as wall tiles in the bathroom. Now we are considering laying them everywhere in the basement as well. Would that be "too much of a good thing"?

After saturation comes the p*** limit. By the way, to me it looks more like 60x60 in the picture. If I could get tiles below the feared price, I would allocate the savings to the fund for extra expenses elsewhere, rather than indulging in gluttony with it.

For me, the picture actually looks more like 60x60.

Yes, certainly, this is just a sample image that quite well captures the color.

Thank you for all the tips so far.

After saturation comes the p*** limit.

So the suggestion would be different tiles in a different size? Or laminate, design flooring in the basement...?

To add another question: What color would you envision for tiles in the basement? Surely a similar natural stone look makes sense, white slaughterhouse tiles would probably not be suitable...

in which, due to the lack of daylight from above, you cannot look directly, one could also resort to something simpler.

In our place, from the upper floor (roof window in the slope for more light), if you look diagonally, you can see all the way down to the basement floor. The staircase is kept open, i.e. no board between the steps (I don’t remember what that’s called anymore), dirt would fall from the very top to the very bottom. For me, the question is whether it should look the same visually in the basement.