Share development costs or regulate them to ensure future security

Good afternoon everyone,

I have a legal matter.
It probably makes more sense to speak directly with a lawyer, but maybe someone of you has already had a similar case.

It’s about the fact that I own another plot of land besides my developed property.
This one is currently not yet developed.
Next to my undeveloped plot of land, there is also a large undeveloped plot belonging to my neighbor.

Both my neighbor and I have access via the roads in front of our properties.
Now I want to develop my undeveloped plot and will do this via the path that is owned 50% by both of us.
This is also fine with the neighbor.

I asked the neighbor if he wanted to participate equally in the development since his second plot is also undeveloped, but he declined.
That’s fine with me – it’s his decision :)
Now the neighbor said he will simply "connect to" my sewer connection in a few years.
I find that quite questionable, as I am now bearing the entire cost for the development (round about 30k total).
He doesn’t want to participate, but wants to be a beneficiary...

Therefore, I’m wondering if I can somehow arrange a fair participation from his side afterwards.

How would you assess this?
Talking doesn’t help – he currently does not want and will not want to participate and also does not want to share costs later.
In his opinion, he can use the sewer connection located on our path.

Just from my perspective, that would be quite unfair. But morality and law are two different things :)

Attached is a sketch, it explains things much better than my text.

Thank you very much for your input.

What exactly or why do you want to develop the property? It is practically developed. It has an access road, and all the utilities are not far away if it is to be built on. What’s the point of laying water and electricity to the property boundary now? Unless you want to build, it is a wasted effort. If you want to sell or build on it now, then it is your personal project. Why should your neighbor feel compelled to join in now if their future plans are different?

My son wants to build on it.

I’m saying, the neighbor doesn’t have to participate, but in 5 years just using my paid cable connection without paying would be bold.

Connection lines are sewage, water, electricity, and telephone, and at least for the last three, the main line is always branched off today. Then your neighbor only saves the sewage. Are the two developed properties connected via the path? Is the sewer large enough for one or two more houses?

Both already developed plots are accessed via the street in front of the respective house and not via the path. Both developed plots are largely paved. The shared path is not. It is not even gravelled. Therefore, the wastewater pipe is to be laid over the path.

How would you rate that?

I would laugh about it.
I would respond to my neighbor’s profitable stinginess with a calm generosity and let the neighbor do as they please – knowing that I paid for what I got and am not harmed. This generosity costs absolutely nothing.
Why invest quality of life without a mandate and prospect of success in a neighbor’s educational measures? It is absolutely not worth it.

Addendum: Surely, from my point of view, it would also be perfectly appropriate to find a participation solution. It just isn’t the case and the goal is to build the house for the son. The neighbor is irrelevant to achieving this goal.