Floor plan detached house, 2 full floors and a recessed floor

As far as I understand development plan No. 900 of the city of Bochum, the following is noted in the textual version:
"2.2.4 Top floors
...
In general residential areas WA 1, for buildings with flat roofs, an additional floor above the top full floor is permitted, if it on all sides recedes by at least 1.00 m behind the vertically rising outer wall of the full floor below.

That reads harmlessly, but it is quite explosive: read knowledgeably it unfortunately means nothing other than that on four out of four sides there are A. exterior walls (i.e. load-bearing walls) that do not stand on top of their counterparts in the floor below and B. in the area of the setback there is a floor slab making a roof, which requires massively increased insulation effort – among other things with “Isokörben” (R). This will be extremely expensive structurally and energetically, and thus the additional living space of the recessed floor becomes a Pyrrhic victory in terms of price per square meter. If the area of the recessed floor is not dispensable, this would be a decisive argument against this property for me. I see right now I should probably once calculate something like my basement formula also for recessed floors.

Do you have a fixed idea regarding "another staircase" that you can pull out of the sleeve, which is easier to integrate?

The staircase is another problem: because of the retreat on all sides it is also pulled away from the outer wall in the floors below, which can cause quite a hassle, as can be admired in:

The transfer of ownership only happens when the design has been "approved" by the project development company according to the "design guidelines" for this building area. Then a building application can be submitted and therefore the land purchase can be notarized.

We already had such clowning here as well, in the thread by (if I remember correctly, in the Pforzheim area): there one had to apply with preliminary designs of one’s house in order to be allowed to buy the plot. That means a committee like an architectural competition jury reviewed the plans to check if they were nice enough to be considered worthy of construction in the ensemble with those of the neighbors. Only after the "approval" (“Gutbefund”) of this committee (I had never heard such a Swiss-sounding term before in Germany) was the humble petitioner allowed to submissively acquire the highly imperial consecrated building ground. Good gracious, I had hoped such nonsense was at least a unique case – is there seriously such a thing now even in the Ruhr area, which is usually considered the last refuge of the "normal people"?

for a family with four children. You certainly don’t find that on catalog page 17...

No, page 17a, you have to unfold that ;-)
I would not throw in the towel because of “the two additional children” when it comes to finding something among standard designs: in my guess such designs for two-child families plus a granny flat often can be adapted quite well with minimal intervention. Unless they are quadruplets, with four children there are usually some who will be ready to leave home quite soon or are not ungrateful for not having to be too close together with the younger siblings.

I can understand the idea of downsizing. It will probably inevitably come down to that in the end when the offers from the general contractor/general contractor (GU/GÜ) are available...

Houses are like breasts: downsizing is the significantly more difficult operation. The same applies to the procedure of adapting plans after offers: that is the very bad wrong order. The tendering always follows the planning, N.E.V.E.R. the other way around!

You could inquire at a company from Marl, whose name begins like the vehicle registration plate in Sprockhövel. They don’t have a catalog, and are basically rather in the mid/upscale (not luxury) segment.

Always these riddles – EN or WIT?

The (junior) boss also has children, by the way, but he is a BVB fan.

That doesn’t bother me as a damn Prussian at all if someone beats Bayern at their own game ;-)

Gentle goddess, I had hoped such nonsense would at least be unique – is this seriously now already happening in the territory that is generally considered the last reserve of "normal people"?

GE set the example, and BO is now happily joining in. :rolleyes:

Always these puzzles - EN or WIT?

I won’t say. :p But with WIT and the other clues, it would be hardly possible to find anything. ;)

Thank you all for the helpful and valuable tips! I will try to take them into account.
Best regards
Stephan

Dear community and experienced homeowners,
you helped me enormously in March with your advice regarding the planning of our single-family house with four (!) children’s rooms. Many thanks again for that!
We are already quite satisfied with the current planning status, but I fear that both my wife and I have become blind to the situation after all the discussions. For this reason, I would like to have your unbiased and fresh view on our latest planning status.
The following conditions apply:

[*]The building plot is approx. 11.6m wide and 12.5m deep
[*]The property has a south-facing orientation and is flat
[*]The ground floor may be extended by max. 2m up to 14.5m in depth, but the first floor must be within the building plot with 12.5m depth. The roof area created above the ground floor may be used as a terrace
[*]Setback areas left and right each 3m
[*]Carport/garage must be set back 2m behind the facade
[*]The building plot is limited by building boundaries
[*]Maximum building height from upper edge of ceiling (OKE) 9m
[*]Basement + 2 full floors + 1 not full floor with flat roof
[*]Non-full floor (setback floor) must be recessed at least 1m on all (!) sides

In particular, I would be interested in your assessment of the following design questions:

[*]Do you have other ideas to integrate the staircase into the floor plan while considering the setback of the setback floor? It may be prominent, but must not start/end in the living room. We have excluded straight staircases because, in my opinion, I do not have enough space for it to really make an impact...
[*]How critical do you see a stairwell without natural light entry (except through windows on the 2nd floor)?
[*]I find the generous access of the 1st floor quite attractive for hanging pictures, sideboards, spaciousness, etc. Do you still have an idea to optimize this without giving up the generous character?
[*]Two bathrooms for four children (including three girls ;-) I consider necessary. Do you have a different opinion other than “three bathrooms for three girls” ;-)?
[*]The layout on the setback floor is somewhat “intricate” due to the location of the staircase. Any suggestions to improve this and at the same time orient the bedroom and dressing room (which is more of a multipurpose room) facing south?
[*]We find horizontal window formats more appealing (mainly because of the resulting space for desks with a sill height of 90cm). However, the arrangement could look a bit “wild,” what is your impression, any tips?
[*]What possibilities can you think of to loosen up or give structure to the facade (street side) through (plaster) colors/materials?
[*]We want to integrate the carport (possibly it will also be a garage) into the facade of the house. We thought of wooden slats in the area of the setback on the ground floor, which continue over the garage door so that a continuous wooden surface is created, which contrasts with the plaster facade. We would pick up the slats again in the utility room on the left side (bicycles, trash bins, etc.). Do you have further ideas to solve this aesthetic problem?

Since I know there are many technical experts here ;-) finally a few tricky (construction) technical questions:

[*]Due to the max height of 9m and the required parapet (0.4m), there remains “only” approx. 2.5m clear room height per floor. The floor construction height is assumed to be 19cm on all floors including underfloor heating and covering for a KfW55 house with heated/insulated basement. Do you see a possibility to gain room height with a slimmer floor construction? Is a 19cm floor construction really necessary for the basement and the other heated floors? Possibly this is necessary alone due to wastewater/ventilation pipes, cables?
[*]The exits on the 1st and 2nd floors should be as threshold-free as possible. This seems technically somewhat demanding since there is living space under the terraces. Do you have experience with this or how this can be technically solved in a solid way?
[*]Wall construction: We plan for KfW55 with 17.5 cm limestone sandstone + 14 cm ETICS = 31.5 cm. That is not far from a monolithic construction with 36 cm stones, which I would also like. But the general contractor does not like this (among other things because of load transfer, sound insulation)... I am aware that this question cannot be answered generally due to energy calculation, window surfaces, etc., but maybe you still have some suggestions: What other possibilities do you see in wall construction to achieve at least KfW55 without producing significantly thicker walls?
[*]Subsequent division into two/three units. Unfortunately, our current staircase concept is only conditionally suitable to split the house later into several units. Do you have spontaneous ideas on how this might be accomplished?

Attached are the documents to better visualize the conditions:

[*]Site plan
[*]Floor plans
[*]Section
[*]Elevations

Many thanks for your fresh thoughts on these questions! I am sure you have valuable hints here and there that we would no longer think of, as we cannot see the forest for the trees...
Have a nice weekend everyone!
Best regards
Stephan

You greatly helped me with your advice in March regarding the planning of our single-family house with four (!) children's rooms.

Given over six million dead, I prefer the abbreviation children's rooms. Five and a half months of pause is a good time for a thorough revision. You should mention the post numbers of the previous drafts for this.

A uniform setback of the penthouse floor is also a structural burden. Even if it doesn’t become feather-light because of it, I would consider constructing the penthouse floor as a timber frame. Additionally, I once again see a lot of botched patches "planned in," especially in the wall sections between window openings.