Use neighbor's access / Permission in writing? Experience?

Hello everyone,
we want to build a single-family house on a hinterland property and currently have a limited access road.
Details of the restriction:
2.80-3.00m wide street - about 12m along the front house and a restricted clearance height of 3.05m over a length of 5m.

Within the next 14 days, it will be clarified whether we may possibly share the driveway of the neighboring property and thus have a 5-6 m wide access without height restriction.
For this, I of course need to make a written agreement with the owner that we will restore the fence and the driveway at the end. Although I have received some points from our construction partner that I should include, he could not really provide me with much information because he has not had this kind of situation before.
Does anyone of you have experience with such an agreement and can give me some tips? Is a private contract even sufficient here?
Thanks for your support

This must be registered in your neighbor's land register, otherwise you will not receive a building permit due to a lack of secured access. This is done through the notary; something private will not help you here.

It's about the construction time, and after that you would use the 3*3m aisle as an access road, right? I would definitely get professional advice on this. It must be ensured for you that the contract is not terminated halfway. What if the neighboring property is sold during your construction period? I would also budget a generous "usage fee" for the neighbor's path.

This must be recorded in your neighbor's land register, otherwise you will not get a building permit due to lack of a secured development access. This is handled through a notary; something private won't help you here.

I believe with 3m width and 3m height he will manage his development very well. Only during the construction phase it will be a problem to move appropriate equipment through there. For that, of course, no easement or anything of the sort is necessary.

Depends on the state, with us not, because the fire brigade simply cannot get through there. Whether you can get there with your car initially plays only a secondary role.

So the construction site is in NRW and yes, we have already taken the difficult access into account during planning. In other words, smaller trucks have to deliver the construction parts, which are also planned to be smaller accordingly. We would now of course like to avoid this and therefore coordinate with the neighbor. The neighbor would only have to allow us to use his driveway for a maximum construction period of 8 months. Afterwards, we would repair it again. This obviously saves us a lot of money and he possibly gets a newly paved driveway.