Develop building land. Profitability test for beginners?

If there is no pressure to sell:
Wait and drink tea.
With luck, over time the land will become building land.

Thanks in advance for the many answers!

mhm. well, I myself do not want to build there. As mentioned, my main place of residence is about 600km away in southern Germany.

I have already spoken with the municipality. They say there is a certain demand for such building plots and want me to develop it. So to establish a development plan and carry out a land development. Other areas have been and are being developed in the nearby surroundings as well.
The plot is actually quite close to the center. About 250m as the crow flies from the marketplace.

Would it be a possibility for me to get offers from the planner and the utility providers and then add them up? Could one proceed like this to estimate the development costs?

So to request offers from:
Planner
Gas provider
Electricity supplier
Drinking water supplier
Wastewater
Road construction

or would this approach be very naive?

Yes, you want to develop land and draw up a development plan as a layperson? I beg you, that will go wrong and you will lose money. You only have the chance to determine the value and sell it to a development agency. It will not become building land either. No one will develop it and draw up the development plan if they do not own it. Talk to your bank....

or would this approach be very naive?

Alright. To answer this question, you first have to answer a few questions:

Now a partial area of about 3000 sqm was designated as "building expectation land" in the land use plan.

There is no "building expectation land" in the land use plan. One possibility of what makes a piece of land building expectation land is that the land use plan designates residential building land there and the municipality has indicated that it intends to create building land there. That apparently happened here.
- Has a new land use plan been drawn up or has an existing one been changed?
- Who ordered the change and why?
- Is only your field affected?
- How did you find out about it?
- What are you studying?

Maybe you know a good book

Federal Building Code (Baugesetzbuch)

So, I just checked again, it’s about 5,600 sqm, not 3,000. The area is listed as a possible expansion area. And I know that in the same street just two months ago the development plan for a similar area was approved by the municipal council. Attached is an aerial photo.

- Has a land use plan been newly established or has an existing one been changed?
- Who initiated the change and why?
- Is only your field affected?
- How did you find out about it?

Unfortunately, I can’t really answer these questions.
I don’t know when it was last changed.
A distant relative told me about it.
I also went to the office and looked at the land use plan. The area is shown hatched. I don’t remember the exact designation now. I thought it was expected building land. Possibly also expansion area.

- What are you studying?

Geography

You want to develop and draft a development plan as a layman? I’m sorry, but that will fail and you will lose money. Your only chance is to determine the value and sell to a development agency.

Your answer is somewhat reproachful but interesting in terms of content. I didn’t know that it is so impossible for a layman to do something like this. I thought you just hire various companies to carry out the different steps.
Why do you think it is bound to fail?
Ah... so that means I don’t hire a development agency to develop the land and pay them for it. Instead, I sell the land to them and they sell it later at a higher price. In doing so, I surely sell it at a much lower price than if I had developed it myself... hmm...

What options do I have left? Am I seeing this correctly?
A. Have a planner design it and rezone it to building land. Then take care of the development myself. (seems very difficult)
B. Have a development plan drafted and then sell the land as undeveloped building land to a development agency.
C. Simply sell without development plan and development. As agricultural land. For peanuts.
D. Don’t sell
E.? F.?
Other possibilities?
What would you do?

Thanks in advance for your help!
That already helps me a lot.

unfortunately I can't really answer these questions

Okay, then I’ll join the answer of the Nordlicht and answer your question

or would this approach be very naive?

with "Yes".

Why do you think it will definitely go wrong?

Imagine you inherited a Golf 1.2TSI. Now you heard that you could sell a Golf R for much more. A car dealer confirms to you that a Golf R brings in much more and considers a conversion to be reasonable. Now you ask in the Golf forum if anyone knows a master mechanic who can advise you independently, if anyone can recommend literature on the conversion measure, and if obtaining offers for engine, transmission, and TÜV approval would be a viable approach.
Maybe this example makes clear to you that the conversion will never be worthwhile for you, since the Golf R can always be produced more cheaply on the factory assembly line and only an experienced workshop without time pressure, by using occasional excess capacities, can develop an economically sensible project here.
As an aspiring geographer, you are not so far away professionally. So if you can imagine working in the field of land development in the future, you can of course practice here (albeit with great financial risk). Then talk again with the municipality and ask the developer of the other B-plan which steps he went through, how big the preliminary investments were, and what resistance occurred.