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For the transfer of the sketch into a buildable plan, he says and calls it "pre-planning".

I'm curious what he charges for that. Keep us updated. I wouldn't start being stingy at that point.

Correct. However, a floor plan multiplied by the provider's standard construction service description

Ahoy there, Captain Obvious!
Please save yourself such pedantic and hardly funny pseudo-explanations that nobody needs.

Then the OP can simply calculate sqm x €2,750 + construction incidental costs and be done with it. And which standard the OP wants, he does not even know yet, since he has just put a few lines on paper. I think he is a little too naive in his approach.

: After almost 30 years in the real estate industry, I consider myself a financier / home builder / project developer and landlord who provides reasonable explanations. Just because something works for you sometimes, it is not the rule. It is also supported by the fact that the OP received only one answer despite several inquiries, and that answer was: Give us your idea and we will make a plan out of it.

Otherwise, I recommend you rethink your tone. With well over 8,000 posts, I do not write pedantic rubbish but want to help home builders.

So you want to "relocate" the building envelope while complying with the site coverage ratio? - and under this condition the building authority already agrees to the exemption in advance??

Areas that were previously not buildable are being built over while complying with the site coverage ratio. The non-buildable areas are within the planning boundary. The building authority now confirms their willingness to exempt these areas by official decision. They had suggested that we inquire about a roughly considered house or its position via a preliminary decision (BVA).

In the preliminary draft stage, and even more so in the brainstorming stage, an exterior wall is forty centimeters thick and interior walls (which are initially assumed to be load-bearing here) are twenty, (period, as a former chancellor would have added). You don’t need to consider the Pentecost Tuesday in leap years here for a long time.

Oh, thanks for the tip!

I am curious what he charges for it. Keep us posted. I wouldn’t start being stingy at that point.

Absolutely not. I don’t want the cheapest house either, but one with a good price/performance ratio, and the plan should be the same.

I think he is a bit too naive in his approach.

True. But how does one approach something like this professionally without experience? I have to start somewhere...

I have to start somewhere...

That's why you're asking here. Nevertheless, I would seek a conversation with an architect - initial consultations are free. You can also plan professionally with an architect and later have a builder carry out the complete and individual (comprehensive) tender. Your risk is that you might receive offers that look really good. But you only get built what is agreed upon. A low offer can always lead to additional charges, which in the end become expensive. As a layperson, this is hard to oversee.