Assessment & assistance semi-detached house, approx. 180 sqm in DIY floor plan

If you want to make the house 12 m long, but the building boundary only allows a 12 m window, do you already have positive indications that the terrace will be approved? Because, as far as I know, the terrace must be approved outside the building boundary by exemption.

Learned… Where? Of course, if one wanted to, you could basically install different stairs. Why do so few builders do it? Because there is a dependency between the stairwell, static structure, and ceiling. A staircase must be supported by something; this works in a standard house construction through load-bearing walls. Transverse or the other way around, that depends not only on the load-bearing walls but also on the staircase. Or you focus on the staircase and then adjust the load-bearing walls accordingly.
Stairs with a central winding either have an additional load-bearing wall in the stairwell, a static column, or a large open stairwell. But somewhere the upper floor must be supported and therefore the ceiling must be braced, and not just at the outer edges... With a lot of money and cash, you can plan more freely with great effort, but that is not possible with €550,000. You would rather do that in an open house over 280 sqm like with .
Then, of course, you cannot build over stairwells. One or two steps are okay. You lose headroom because of this. Walking up a staircase with too small a stairwell does not work and no professional would plan or build that.

By the way, it is also not exactly visually appealing when you go from the ground floor to the upper floor and then have to look past a cramped stairwell.

Anyway: I am rather unreasonable too when it comes to great aesthetics. Spatial effect can create more size and airiness than 1-2 sqm more. However, you probably have to somewhat or completely yield to your own family planning and give up one or more wishes if you want to live the daily routine reasonably comfortably with 4 people under a DH roof over the years.
That includes room usage and necessary storage and storage space.
Your staircase steals you several sqm from the open living area without benefit. You expand the hallway into the open living area through the staircase location, which is practically no longer usable, except for placing a small dresser in the higher part of the stairs. The kitchen has a staircase hall flair; no one wants to play there, and daylight is hardly available in this area either.
While a space-saving staircase integrates quite well in a RH/DH, this staircase location has rather disadvantages.
As already mentioned above, the execution is rather questionable.

hm, thanks for the detailed answer! That’s exactly why I’m here... for such helpful answers :)

GF
Squeezing doors into a corner of a room is optically rather unpleasant for a room. Furthermore, on the left side of the plan there is fundamentally no space for furniture placing across the width. Any furniture there becomes a barrier. And yes, your wardrobes will probably _not_ suffice for all 4 of you. A dresser or an additional coat hook is hardly possible there.
Is the kitchen enough?
The hidden door to the freezer room also steals 2 tall cabinets… slender fridge and oven remain then with 2.40 m working surface. Island could be that long anyway.
The dining table is quite far away from the kitchen activity. There is also a free space there that does not really contribute to the room layout.
The living room is only suitable for a narrow TV cabinet.
UF
Children’s rooms should be oriented to the light and here to the south. The bedroom can share the side with the bathroom. Again, the excessive length of the staircase backfires, so that you cannot place a door where it is needed.
Bathroom has unnecessary walking area in the entrance area and thus the bathroom loses about 3 sqm of usable area.
Stairwell is built over.
Attic
You have a lot of space without fridge where you cannot stand. The bed will probably be poorly usable like that. Ideally, you plan the roof slope and standing area into the furniture planning. You will have a manageable room in the attic, maybe 4 x 4 and a narrow room as a freezer/utility room plus storage/attic space. I do not see a corridor for space reasons. If you plan with many windows up there, it can of course become a friendly room.

GF: It may be a matter of taste, but I personally find it better if there is just a wall with the door open and not a cabinet that you can only use if you close the door again. Therefore, I deliberately tried to open the door towards the wall and not into the room.
The kitchen is planned in the floor plan with 5 m length (minus door to pantry), island with 2.2 x 1.1 m. Shouldn’t that be enough?
UF: I don’t like the bathroom either, it definitely has to be better. Both kids go to the south.
Attic: According to the development plan we should not have any knee wall, we might build a dormer on the south side to create more space. Generally, not much will happen up there in the next years, as it will be for guests or when one of the kids eventually needs to spread out.

You are limited by a semi-detached house: a small plot and building window here, no west side, entrance and staircase location is almost predetermined if you want to get the optimum. I think it is wrong to want to install a gallery staircase and give away valuable space for it. At least for a staircase that is right in the middle but excluded from the action despite being near the kitchen. It would be an alien element in the house here.
I am of the opinion, and have seen some projects where much more was made out of a MRH than the standard requires. But you do not have to reinvent the RH/DH to create airiness and/or generosity.
A nice classic but modernly executed staircase, daylight on the upper floor and no walls you bump into, that’s already half the battle. A HO can go all the way up, then you can also take care of laundry in breaks. Large gable windows up there would make it hard for the resident to decide where the favorite reading spot is.
If you cannot accept a DH or the restrictions well, I would suggest continuing the search and selling the plot again.
If you do, take some of the suggestions in hand and try to make the design interesting with simple means that also works then.

Do you happen to have a floor plan that creates airiness/generosity without reinventing the wheel? I just lack ideas there….
Selling and continuing the search is not an option. Either we win the lottery again, an unknown aunt dies, or our life expectancy rises to 120 years, otherwise it is at least impossible to find something here.

If you want to make the house 12 m long, but the building boundary only allows a 12m window, do you already have positive indications that the terrace will be approved? Because, as far as I know, the terrace outside the building boundary must be approved by exemption.

I always orient myself based on the neighboring buildings. If the house opposite has utilized everything the same way and still has a terrace, it should probably work for us too, right?

Therefore, I simply conclude that certain companies that exclude this do not want or cannot accommodate such customer wishes outside the standard.

They could. But of course with an extra charge. Because in the standard, the attic is often only a cold roof.., so of course no wiring or heating is possible. The attic conversion is an optional extra!

an acquired taste.

And that’s putting it mildly. I can think of other words.

Ground floor: It may be a matter of taste, but personally I find it better when there is simply a wall behind an open door and not a closet that can only be used when the door is closed again.

I don’t think you can or want to do without the necessary standing area in the long run. When planning a house build, you also take into account that you might furnish differently at some point, or need to store or accommodate more over time. That’s why you plan for sensible standing room.

Do you happen to have a floor plan without reinventing the wheel that creates airiness/spaciousness? I simply lack ideas...

I have many, and if not, then I plan them ;)
But not with different stairs. That amateurish mishmash for me would be a faux pas, a negative eyecatcher that achieves the opposite. Given the width of the house, I could imagine a straight staircase running transversely. But that would currently be a theoretical experiment ;)

Which drawing program can you recommend for a layperson's floor plan?

Pencil, ruler, and graph paper

The "background story" can be found see ***** and

The top post does not belong to me

Oops, right, it was that one:

What is statically feasible does not depend on the company, but on the construction method. In "solid construction" with a staff discount at ThyssenKrupp pretty much everything is possible, also with a platinum card from Sultanbank – but that should not be abused for dreamy layman planning. It’s not like you have to bury your dream house right away just because you accept the framework of a somewhat economical structural calculation. "Integrated beams" are actually no longer such, and through tricks they often become easily twice as expensive.

Being a construction f*rma is no shame, you don’t need to censor the names. I have also already encountered the lady to quit dealing with, fortunately well-known general contractors are not as bad as their sales representatives. But for good reason, I recommended the relevant semi-detached and terraced house developers to you because they are considerably more useful for inspiring workable construction proposals: they build entire baking trays full of semi-detached and terraced houses en suite with the most sophisticated variants. You want to build in a more relaxed width than their models, so you can copy these with a further tightened belt and get functional floor plans with "business" instead of "economy" elbowroom. If you come to a general contractor with a desire for a semi-detached house eight or eight and a half meters wide, they take from their drawer a detached single-family house with a bricked-up window side – the disappointing result is inevitable.

Stairs require a headroom that is about half a meter less than the usual clear room height. From this derives a potential of up to three risers of acceptable overhead clearance. And indeed you can switch stair shapes between floors – but from X to Y and from Y to X is not equally easy. And in most cases, it also causes you to "lose" both stair floor areas in the two affected floors. Even the most experienced planners do this only in exceptional cases, and as a beginner you better leave that alone. You can see on your Roomsketcher image illustrated in exemplary fashion that you even exceed the imagination of the software. Your request for hints about other software is cute, but this is not where the problem lies.

Pencil, ruler and graph paper

Thanks to the Carolingians, you can also do without the ruler. By the way, that’s my favorite professional tool. For details such as stairs, you can switch to the scale 1:50, i.e. four squares for one meter.

How do I get the concrete number? If we have a max eaves height of 6.5m and a gable roof of 30 degrees, how much distance do we have to keep or maximum build on a lot width of 11.5m?

You have to calculate the concrete number yourself, which is not quite trivial. But I generally advise never trying to squeeze building windows down to the centimeter. You get the concrete formula by combining two sources: the respective state building code tells you your minimum of 2.5 or 3.0 meters and the house height h in the weighting of 0.4 or 0.5. From your specific development plan, you must then deduce to which reference height the house height is to be "applied".

If you want to make the house 12 m long, but the building boundary allows only a 12m- , do you already have positive signs that the terrace will be approved? Because, as far as I know, the terrace outside the building boundary must be approved by exemption.

I always orient myself on the neighboring development. If the house opposite has also exploited everything and also has a terrace, that should work for us too, right?

An exemption would be required, and an exemption certificate would be exactly out of the question. Whether the neighbors applied for an exemption is as invisible from the result as whether their terrace is an illegal construction. Quite often, the building authorities tolerate the pure paving and turn a blind eye until you want to put a roof on it.