Building plot "fully developed, costs for private road?"

I have no desire for expensive road construction contributions shortly after moving in.

That is a different issue: The two homeowners with the plots on the public road are also direct neighbors there, and with the communal street you are all collectively indirect neighbors again.

I wouldn't be so sure that the road construction works are included here.

By "Erschließungsanlagen" I only understand the connection of the private road to the public roads.

How long is the street?

It should also be considered that not all residents may plan to build promptly. Then there will initially be fewer heads. On the other hand, maybe an agreement will be reached faster.

We also have to build a private road: It's easily 20k €.

It should also be noted that not all property owners may plan to build promptly.

The slowpoke will not make themselves popular, as they delay the completion of the road.

Then there will initially be fewer people. That might make it easier to reach an agreement.

For the plots not yet sold, the seller will still be present at the meeting – they are not without a vote.

The procrastinator will not make himself popular, as he delays the completion of the road. For the plots not yet sold, the seller will still sit in the meeting himself – they are not without voting rights.

I must admit I am not familiar with that. I once considered a similar case (2 plots / 1 road) and was told that as long as the second one is not sold, I have to bear the full costs and can only recover them proportionally once a buyer for the second plot is found.