Interpret building plan / is it even feasible?

We are in contact with an architect. He said that it is currently simply difficult to provide a realistic cost estimate. With a prefab house, one would be more on the predictable side… of course, we would prefer an architect. But our budget is not unlimited.

Did he really say “prefab house”? You are interpreting too much instead of reading properly. I only made it to about the third line. Apparently, it is a sloping plot where you are allowed to build one story plus a basement. In addition, one side of the roof may also have 60+ DN. …. It’s all good :)

Please provide the plan excerpt from the development plan of the property and the textual additions.

The text mentions a slope. Are there any height specifications in the plan?

6 m eaves height doesn’t sound too bad. Rather like 2 floors + roof. The development plan also seems quite old. What does the municipality say about deviations?

Have you already purchased the property?

So far, there is nothing against a prefabricated house/prefabricated solid house for us. Except perhaps some "design". We have concerns that due to the development plan and soil conditions, a prefabricated house might not be possible or only with many changes, which would be reflected in the costs.

Unfortunately, we are total novices and cannot properly interpret the development plan. Therefore, the question in the forum.

We have not bought the plot yet. But we want to buy it. Unfortunately, it is subject to a bidding process.

So far, there is nothing speaking against a prefabricated house/prefabricated solid house for us. Except perhaps some "designs". We have concerns that due to the development plan and soil conditions, a prefabricated house may not be possible or only with many changes which will be reflected in the costs.

Basically, you have to distinguish between the planning and the construction method. Catalog houses (standard models) are available both as solid construction and in timber panel construction. Likewise, you can build an individual house both solid and in timber panels. At first, both variants are basically comparable. Parts in contact with the ground are nowadays made of concrete anyway.

An expensive option is to take a catalog house and then adapt it with 15 changes. In that case, a freely planned house is cheaper, but it is also offered by many prefabricated builders. Adjustments due to unfavorable plot profiles or soil conditions are expensive for both.

Unfortunately, they are total rookies and cannot properly interpret the development plan.

Then this behavior is not only rude but also utterly stupid:
(and I'm out - clear, right?)

Then this behavior is not only rude, but also extremely stupid: (and I'm out - it's clear, right?)

In the case that one doesn't even have the property yet, I can understand the behavior. But still, all the information must be put on the table. The OP's inexperience alone calls for help here. One can anonymize the details if there are concerns that another bidder might be reading along.