Surveying Services - Cost Differences

I just realized that the affordable offer does not include an official site plan and that the surveyor is not authorized.

Now I am trying to find out whether a non-official site plan is sufficient for our building application.

Definitely not.

Very helpful comment!
Thank you very much for that

You are also welcome to check for yourself. Keyword: § 3 BauPrüfVO

I have already done so. And no factual element is met that would necessarily require an official site plan.

Then I do not understand the question. Besides, I thought you wanted to submit a building application. For that, building plans are required, and that is what the above-mentioned regulation is about.