Tile planning single-family house - slip resistance/strength/quality

Yep, that's how it is with us. Don't worry. You can walk barefoot on underfloor heating.

However, I would tile hallways and living areas the same and throughout. It looks more spacious.
The gray tile seems quite deceptively sensitive to me. You'll see every grain of sand on it.

So in the hallway, I would never choose the same tiles as in the living area because of the look and also the price. Since we want a wood look in the living area anyway, this question doesn’t even come up. I always find gray pretty stylish in the hallway :)

Yes, you're right - this tile could be quite deceptive. But I also find it hard to find a gray tile where you don’t immediately see every little grain :D

Yep, that's how it is with us.

Same here. The children have worn out quite a few pairs of tights this year.

No problem. With underfloor heating, you can walk barefoot.

If you have an old building that you heat from September to April with a 40-degree flow temperature, then yes. ;)
Otherwise, I would be cautious and say it depends. Especially during the transitional season, it can be quite cool on the feet.
On the other hand, our children rarely care about that, slippers are always lying around somewhere and the kids jump around in socks/tights. Which in turn caused the wear :p

The gray tile seems deceptively sensitive to me. You will see every grain of sand on it.

Do you mean this slate-colored tile? We had it in the old apartment. This one here also doesn't look completely uniform, but I didn't find it that bad.

Since we want a wood look in the living area anyway, this question doesn't arise either way.

Wood look is also "just" tile. We even have the expensive ones in the utility room... a good investment in the long run. I would constantly be annoyed about the transition and feel forced to close doors ;)

If you have an old building that you heat from September to April with a flow temperature of 40 degrees, then yes. ;)

We don't have that. Everyone says tiles should be cold. With us, that's not the case :) The transitional period, yes. But not in sunny weather: then the tiles warm up through the windows and store heat quite well.

Wood look is also "just" tile. We even have the expensive ones in the utility room... a good investment in the long run. I would constantly be annoyed by the transition and feel forced to keep the doors closed ;)

Mhm, I somehow don't understand that? What do people do who have laid parquet and have tiles in the hallway? Or the majority who have a transition from living room parquet to kitchen tiles? I personally don’t find that nice either, which is why we ultimately decided on tiles in the living-dining-kitchen area.

However, uniformity with the hallway is not important to me at all... That would never bother me personally. But I also don't find it very cool to use different floors in closed rooms :D

Mhm I somehow don’t understand? What about the people who laid parquet and tiles in the hallway?

... because it was the answer to your statement: It’s not about wood, but about tiles that are insensitive due to their color - tiles with a wood look.