Garage extension on own property with building prohibition

Hello everyone,

we are new here and hope to get help with the following problem.

A brief introduction:
We are a young married couple (30/27 years old) and would like to realize our own home next year, then with a child.

Circumstances:
The attached picture visualizes the intended construction situation.
The area on the right in blue is supposed to represent the main house, and the narrower garage extension would be on the left.
The parcel 3423 already belongs to the family.
The parcels 3423/2 and 3422 would be purchased.
Historically, there was an exchange of various parcels with the church,
in which parcel 3423 was acquired and due to the view of the church,
a building prohibition was registered in the land register.
We have already contacted the church, and they "in principle agree to a development."
However, a payment would have to be made because the areas were exchanged as purely agricultural land back then,
so we would need to "show understanding" in this regard.

We have now abandoned our original plan to build solely on parcel 3423 and would like
to purchase the mentioned areas from the municipality. However, we would still like to build the garage,
as shown in the attached picture, on the property with the registered building prohibition.

The church would be willing to have the building prohibition removed from the land register by means of a cancellation request.
According to a phone call, the amount for the payment would then be based on the land value and the buildable area.
Since the property is over 800m², that would be a huge amount of money.
As can be seen in the picture, the property is only between 5.5 and 12.5 m wide – less suitable to badly suitable for conventional construction. Moreover, it is subject to a strong slope.

Are there any ideas on how to proceed with the church to avoid a payment altogether?
Or are there any known precedents?

We have also considered simply submitting the building application, but at the latest at the notary appointment,
it would be noticed that an easement (building prohibition) is registered.

Many thanks to all experts in advance :)

You want it, then pay for it. Plain and simple. What price per sqm do you pay for [Bauerwartungsland]?

You will have to negotiate with the church and come to an agreement. You have no other choice.

The church congregation probably cannot lift the building ban for free. As the trustee of the properties and assets, it is responsible for ensuring that these are not sold below value. This is different from private individuals.

that would be a huge amount of money

Use less subjunctive and provide concrete numbers. If you don’t have them yet, ask for them. Ideally, also establish the overall context of the construction project so that a comparison can be made, and possibly discuss alternatives without developing the 3423; from the excerpt, one might guess that this could also be possible. Knowing the exact wording of the "building ban" would also be advantageous.

I would negotiate the contract with the church so that payment is made only for the actually newly built-up area. After all, the rest remains garden land as before. This can also be specified as such.