Tiling in the upper floor of a new building - no stairs available

why don't you take some wood and quickly screw together a staircase? 1 day of work, a cordless screwdriver, and a few screws. That's all it is.

You can't get it up otherwise so easily.

Go to your future stair builder and ask for a construction staircase - he will certainly install something like that for you at short notice.

Put a ladder up and carry the stuff up yourself. It takes strength and sweat but you gladly do it for your little house...

Is the tile transport the problem of the tiler or the BG-compliant safety for his employees? You can solve the former by doing it yourself (see suggestions), but not the latter, for which only a fall-protected ascent in the form of scaffolding or stairs helps.

Maybe this question is too amateurish, but how do I best get the heavy tile packages up using a ladder?

Have you never seen roofers? - they have such lifts that look like a ladder without a basket and fire truck.

How many tiles are we talking about? 2 bathrooms? Carrying them yourself...

Entire floor coverings: Properly nail together the stairs (have it done).