Additional costs for residential units

The floor height of 2.7m is planned very optimistically. Who still wants ceiling heights of 2.4 m today? Aside from that, how is the ceiling supposed to be constructed with 30 cm? Generally, 3 m floor height is commonly planned today.

The plot history still sounds a bit strange. It is 'qasi reserved' but you don’t know where it is or what it looks like? The development plan is also unknown.

Various plots are expected to be released for purchase by autumn. One of them is certain to be mine, but the exact shape, location, and precise size of the one I will get are not yet fixed. Therefore, I do not have exact data here yet, but I also do not want to start the entire planning only when that is decided. It is possible that I will have to adjust the plan later (depending on the orientation of the plot), but at least I want to have a first battle plan beforehand.
For example, this "modular principle" that you reject is something I want to think about thoroughly beforehand, whether it is feasible or not. I do not want to start making such fundamental considerations only after the plot has been purchased.

About the revolutionary 'modularity'

No idea if it is revolutionary. I don’t think so. Basically, the goal is simply a floor plan that can be used in different ways or whose three levels can possibly be combined with each other.
At least I wanted to try that. Of course, it might not be possible or the architect might immediately dismiss it. But I don’t think so, because about 5 years ago I already made a similar attempt (but family reasons prevented the realization then) and the architect considered it feasible. Back then, however, on a much larger scale (more floor space, much bigger plot, but a similar principle).
Now I have revived the idea on a smaller scale, also because the plot sizes are no longer what they used to be (at least not here for me).

As we often notice here, it is counterproductive to show up at the architect with your own plans.

Okay, that’s quite a statement. So far I have assumed it makes a lot of sense to already have a (rough) plan so the architect can immediately see roughly what the goal is. Then he can either crumple it up or say, “this works, that doesn’t, this works but a bit differently.”

For design reasons, city villas are usually built with a 20-degree roof pitch. 35 degrees is rather unattractive.

I know. However, I just wanted to try something extravagant here. The house itself is relatively "boring" in terms of its outline. I at least wanted to plan and visualize the roof. (I would be one step further if I had already transferred this to my planning software, then I could see how the proportions look, also with different colors for the roof/walls.)
It might be that I then see that the pitch does not look good. Maybe I’ll like it. We’ll see.
In our area, there is a multi-family house (although three stories) with a tent roof with such a pitch. In my eyes, it doesn’t look bad (though it could also be due to other proportions).

Say the house height quickly again. I don’t want to search. You can also measure it yourself in your sketch. Is the knee wall feasible? You draw one at about 1.5 m???

Sorry, I’m probably still quite inexperienced. From where do I measure the knee wall? From the inside or the outside (which differs because of the roof pitch). Outside it would be about 70 cm, inside about 100 cm, according to the picture above.

The ceiling height of 2.7 m is very optimistically planned. Who wants ceiling heights of 2.4 m today? Apart from that, how is the ceiling supposed to be constructed with 30 cm? Usually, one plans with 3 m ceiling height nowadays.

So far I have always lived in apartments with 2.4 m. That hasn’t bothered me, so that was the plan so far. Also, I had read that it can be quite relevant for heating effort.
I had also read about a ceiling with 30 cm thickness on the internet. Of course, this might also be false or outdated information. How much would you reasonably plan for the actual ceiling (from the start of the ground floor ceiling to the floor edge of the upper floor)?

Usually, one plans with 3 m ceiling height nowadays.

Okay, I’ll keep that in mind. Does that also apply to the upper floor? Or are there usually differences between ground floor and upper floor?

Or are there usually gradations between EG and OG

You can do it however you want. If you make two residential units, I would uniformly make it 2.60m to 2.70m. Just not 2.40m... that is the legally required minimum height in many places. You are not doing social housing anyway. But in general, restrictions from the development plan or the budget quickly cause changes. It remains that without land and a development plan, all the planning is quickly worthless. A rough plan for your wishes is currently completely sufficient. Please post your floor plan :)

The question about the permissible house height remained unanswered. I have read it in advance, but I don't remember where. Yes, the story height can vary. But living rooms must have a minimum height of 2.4 m. More is nicer. Not always cheaper. It is best to calculate with a multiple of the brick size. For example, 11*238 - 130 floor = 2488 mm glued, then a few mm are added.

According to my (of course amateur) calculations, I come to about 9.70 m ridge height. Up to 10.5 m should not be a problem on the property.

The important thing is the reference point, that is, from where the height of 10.5 m is allowed? We have planned a 1.5-story house, which is 6.67 m high. The reference point is the street. Since our property is higher than the street, despite only 1.5 stories we are already close to 10 m. Our house is already 8.92 m high due to the elevation of our property.

The question is, are 2 full floors and the knee wall allowed?

In the sketch, there are now 2 floors planned with 2.7m each and the roof with 5m. That already makes 10.4m.