Preliminary construction inquiry for land purchase: What should be considered?

First, contact the building authority and ask verbally if this is fundamentally possible? I know that a small residential area is planned to be developed there in the future. However, we would have the opportunity to purchase a plot of land in advance.

In the first step, contact the building authority and ask orally whether this is basically possible? I know that a small construction area is planned there in the long term. However, we would have the option to purchase a plot of land in advance.

I think the landowner should do this in writing, so that in the end all parties involved can refer to one answer.

Yes, you can submit the construction preliminary request yourself, I have done that too. You have to ask questions that can be answered with yes or no. It is best to use the form from the responsible building authority. First of all, it is important whether the plot can be built on according to §34 or if there is a development plan. I guess the former. Then you look at the land use plan to see whether the plot is designated as residential area or garden area, etc. If it is a residential or mixed-use area, then you can build a house there. Additional information about the criteria of the house can be found in the land use plan or the standard land value map, e.g. number of full floors or floor area ratio, etc. If you need help, call the building authority. You can also submit drawings and ask whether the house can be built on the plot as planned. You also have to pay attention to the phrasing of the questions, there are plenty of examples on the internet.

- Does the plot need to be surveyed in advance or is an approximate indication of the plot dimensions sufficient?
I suppose you provide the parcel number. Whether it then becomes smaller does not matter, the size is irrelevant unless you have to adhere to a floor area ratio or plot ratio.
- Is a preliminary request mandatory through an or the developer, or is this recommended?
See above. Private individuals can also do it. Architects know how to ask the questions correctly.
- Is the consent of the owner necessary for the request?
You must have a legitimate interest, e.g. as a buyer of the plot.
- How detailed must the information about the planned house be? Are indications such as: 1.5-storey, , footprint etc. possibly sufficient?
That is up to you. Everything from "Can a house with a gable roof be built there?" to "Can the house have a rainwater downpipe made of dirtied spruce wood in purple color?" is possible.

After a long search, we have now been given the opportunity to purchase a in our municipality. Since the plot is not located in a designated building area or similar, we would like to submit a building pre-application before purchasing. However, as we do not yet have a concrete house design, the question for us is which information is necessary or recommended for a pre-application, specifically:
- Does the plot need to have been surveyed in advance, or is an approximate indication of the plot dimensions sufficient?
- Is it mandatory or advisable to submit the pre-application via an or the developer?
- Is the consent of the owner required for the application?
- How detailed must the information about the planned house be? Would information such as: one-and-a-half storeys, , footprint, etc., possibly be sufficient?

I know that a small building area is planned there prospectively. However, we would have the opportunity to purchase a plot beforehand.

You write that the plot is in the place where you are already established. That should be sufficient to know the local prospects. And you write that a building area is to be developed. What you do not write is: what is it now?

For the yet-to-be subdivided plot, it is best if the seller asks the question (since it can only be answered for an existing parcel) whether there is any hope for a building window on the part intended for sale. The information you mentioned above is sufficient to be able to ask this question. An architect is not formally necessary for this yet, but you do have to be able to draw to scale roughly where the whole thing is meant to go.

Look here in the forum with search terms such as building land, land with building expectation, inner area, obligation to fit in, de facto building window, and the like – then you can already find a lot of answers about the principal procedure. If it is now a §34 area but clearly building land and you only want to build before the development plan is established, then your chances are quite good. If possibly only the part of the plot you desire is still outer area, then you can only dream for at least another five years. I probably have to make a post about what a hard birth a development plan is these days if you currently still have a horse paddock there. Buyers as well as sellers dream very naively there. It is not (also) enough that the farmer just puts a fence behind his barn and sells everything he no longer needs. Without development, there is no prospect of a building permit. If the status of the plot is not yet "right," the building authority can only give very vague or evasive answers. Look here in similar threads about what homework the questioners have been given.

You can be given more precise answers and advice if you show a (sufficiently large-scale) excerpt from an aerial image and cadastral plan and also inform yourself about the status of the land in the land use plan.

I would first like to know whether the property can/is allowed to be divided that easily. I know a case where a property was bought with the intention of splitting it, but this was then prevented by the municipality.

And inquire about the possible floor area ratio and plot ratio as well as setback rules and development plans.