Development of a parcel of a built-up property

I would just call the utility providers and ask. They can usually see in their system where the lines run and give you appropriate tips.

Thank you for your detailed answer. I had thought something similar. Since we are lucky to be directly on the main road, the lines run right along the fence. That’s what I have already found out. I also know that I can only contact the utility providers once I am actually the owner of the parcel. Then we will first make the division legally binding. We will find a construction company, and only when the building permit is granted will I start with the development because if the building permit is denied, there is no point in developing beforehand.

Thank you for your detailed answer. I had kind of suspected something like that. Since we are lucky to be directly on the main road, the lines run right along the fence. That's what I've already found out. I also know that I can only contact the suppliers once I actually own the plot. Then we will first make the division legally binding. We will look for a construction company and only once the building permit is approved will I start the development, because if the building permit is denied, there is no need to develop anything beforehand.

Exactly, but please don't rush anything. If you pick the first best company, you can waste a lot of money. It can quickly add up by the thousands. And don't believe the prices you find anywhere on the internet. Assume €2500 per sqm for the living space. If it should be very high quality, you have to add more to that. But please don't believe that you can get a 150 sqm house for €200k. That just doesn't exist, nowhere, even if a company promises it. Then very quickly hidden costs will appear.

If you take the first company you find, you can lose a lot of money. Start directly with 2500€/sqm for the living area. But please don’t believe that there is a 150sqm house for 200k.

150sqm would be way too big for us, after all, we are just a couple without children. About 120sqm with 4 rooms – that would be sufficient for us.

We have already gone through all the house-building companies in our area and have received corresponding prices; there are already significant differences, not only in the pure house price but also in the additional construction costs. These are often set far too low. Basically, we now just need to decide which company and accordingly work out the cost planning in more detail.

This is our current status and now we are looking for a developer.

Well summarized. Except for your usage of "developer," which is wrong. They sell you a house with land. You already have that, so you are looking for a general contractor.

I also know that I can only get in touch with the utility providers once I am truly the owner of the parcel.

What prevents you from explaining the situation there as a non-owner and having them tell you how it works in your district? already nailed it: inquire at the local building authority,

We are looking for a house building company, and only once the building permit is granted will I start with the development.

Way too late. They have insane waiting times of up to half a year, at least here, and there is no building boom here.

If the building permit is denied, I don’t need to develop anything beforehand anyway.

I would make a preliminary building inquiry...

Is it even customary that we do that ourselves?

The landowner, i.e., the builder, takes care of the plot, the general contractor takes care of the house.

Should a house building company offer that as well?

No, see above.

Are they only responsible for connecting the plot lines to the house then?

No, the GC has nothing to do with that. I find it remarkable how one gets the idea of doing everything solo when there are specialists for that and the building company is brought in at the end. Everything is somehow related to the house: the construction company generally offers, if it is reasonably competent, the organization of the procedure and sequence. It tells you what to do when. What is necessary or unnecessary, what is best, what can run in parallel. During the whole waiting time, you can already start planning. That takes time as well. These are precisely the advantages of "turnkey house construction" with a GC.

The planned house should stand with the short side to the street (short side is 9.84m, long side 12m)

Is there already a plan? Have you already visited an architect? They can also advise you. Not just can, they even should.