What else is added to this object?

That's exactly what I will do. One thing at a time. I will go to the town hall tomorrow. What exactly do I need to bring with me? Or can I simply say that I live on such and such street, etc.

What if there is no [bebauungsplan]?

That's exactly what I will do. One thing at a time. I will go to the town hall tomorrow. What exactly do I have to bring with me? Or can I simply say that I live on such and such street, etc.

What if there is no development plan?

Take the address of the potential building plot with you. Even better would be if you can specify the exact district and parcel number – your father should actually have this information in the files.

If there is no development plan, just ask the person in charge at the office if they can give you information about what is allowed and what is not. So far, I have had good experiences with the officers there. They were friendly and helpful (of course, it also depends on how you approach them).

Oh, one more thing you should do before going to the office: inform your father (if you haven't already) about your plans ;). It would be a shame if you put in the effort and he doesn’t even agree. You don’t want to start a family quarrel after all.

Hello everyone,

I finally found time on Thursday to quickly go to the building authority in our town hall.

After I sat down with the nice man and he took the documents, he said that there is no development plan for my property. It is nowhere recorded what/how/where I am allowed to build and what not. He just said I should look around the neighborhood and adjust my project accordingly!
He sees no reason why my project should NOT get approval.

He told me to create a sketch, roughly what exactly I want to do, how I imagine the whole thing, and then submit it to them.
Now the questions to you, how should I best proceed here? Do you have any tips?
He said I don’t have to make a Picasso picture, just a really rough sketch, with some details!

Have you done something like this too?

Somehow roughly, you have the plot in a drawing; if not, get it!

You can a) draw in your own ideas, but you should roughly keep distances (e.g., about 3 meters) from the property boundaries. b) take someone who b1) knows the subject and can sketch a rough house, b2) an architect who deals with the planning and creates a precise plan.

I would, because you absolutely have no plan:

c) post the plan of the property here (with the surroundings because of the building envelope, etc.). We will see if a "common type house" fits the location.
If you get a positive opinion, you can talk to a builder.
Then, if there are issues, bring an architect on board; they will also take care of the remaining questions.

Translation aid ;):

Last but not least: Since the original poster is so fixated on prefabricated houses. In terms of price, prefabricated houses and solid houses are not that far apart. Often, solid houses are even cheaper in the end than a prefabricated house (this can often be read here in the forum).

Me again: I also had to read this translation aid before I replied...
Nevertheless, the links confuse me afterwards as they make me go in circles, so I do not understand the point.

Just read up on the differences between solid and prefabricated houses... we readers often do not know whether something is written out of conviction or naivety. Solid construction is usually cheaper in single-family home construction...

I only have a site plan, there is nothing more here. Not even at the building authority, they only had one site plan as well.

If I hire an architect, I have to pay them for the drawing, then I give it to the building authority and they say, for example, no, that’s not possible, then I have paid them for nothing, right? I thought I’d just have the construction company come right away, and after we’ve talked about price and so on, they should make the sketch!?

EDIT: So do you think it’s more worthwhile or cheaper to build a solid house for a single-family home? Especially I’m thinking, I want to connect the new house to the existing house, which means the roof has to be continuous, and if you do that with a prefab house, it will be more expensive anyway.
Any recommendations for solid house companies?

I was at a company yesterday that is very well known here. They wanted 350,000€ for a 150m² house (without demolition and so on).