Opinions on the single-family house with a granny flat floor plans

if that’s not building land, you can’t compare it :)

Yes, you can, because there are houses everywhere on it.

It is indeed the case that the children’s rooms are included in the upper floor of the granny flat. If you took more of them, the whole roof shape would be different, and it wouldn’t be cheaper either, because then you would have to comply again with certain building regulations of the development plan.
Bungalows, for example, like the granny flat is, may be a maximum of 4 meters high and must have a 40° roof pitch, if I’m not mistaken.

Well, we don’t know your development plan. Your information about it is too sparse. And in my opinion, you’re mixing up a few things there. Maybe you should take another close look.

Yes, then the roof shape would be completely different. So what?

What does the use of the roof have to do with the development plan? If you’re allowed to build two roofs, then surely also just one.

But if there is no shortage of money and the rest of the land is enough for you, then just enclose a bit more unused airspace. The carpenter will be happy. Maybe you’ll need him for something someday – who knows.

Bungalows, e.g. like a granny flat, may be a maximum of 4 meters high and must also have a 40° roof pitch, if I’m not mistaken.

I consider the latter likely, especially given your strange indication of floor area ratio and plot ratio. Tell me the municipality and the development plan designation, then one can look it up. Different heights etc. for single- and multi-storey buildings typically apply to different building plots.

which storage room is unusable and why? I never really saw it as a disadvantage that a children's room faces northeast. I can't quite imagine it right now, sure, you don't get direct sunlight in there. but with daylight, it's bright enough. especially with a window that's 1.60 x 1.60 meters in size. The dining table is there to eat when guests are around, or maybe in the evening when the kids are older. I don't like counters, that's why the table height. the narrow table in the kitchen is for having a quick breakfast in the morning without having to clear everything into the living/dining room. what exactly do you mean by no direct connection between the living units? basement apartment and main house? It was especially important to me that these are separated and that you can only access them through the entrances to the houses. at one point, there was talk about maybe building a door from the utility room into the basement apartment. but I was immediately against that :)

The narrow corridor on the upper floor. What do you want to put in there? A cleaning supplies cabinet is too deep. In the northeast children's room, you will need much more light. It is too dark in the late afternoon for homework in daylight for some. Ah, the dining area is intended as a good parlor. I maintain that a proper eat-in kitchen without a makeshift solution at the kitchen counter is better. The grandparents are supposed to look after the children. Be it in the evening, after school, or if the child is sick. Also, the grandparents will sometimes need some help themselves. Do you really want to go out in bad weather? There are even multi-generation houses that have a planned communal area. Whether you want the latter is up to you—it certainly has its advantages. A connecting door is a must and not a restriction on privacy.

I consider the latter likely, especially given your strange specification of floor area ratio and plot ratio. Tell me the municipality and the zoning plan designation, then one can look it up. Different heights etc. for single-story and multi-story buildings typically apply to different building plots.

1. Building Heights The reference height point for determining the building height (height of finished ground floor level, ridge height, eaves height) is the intersection of the centerline of the public access road – top edge of finished street surface – with the extended centerline of the respective building plot running perpendicular to the public access road (plot axis)

1.1 The height of the finished ground floor level in the center of the building, measured from the reference height point, must not exceed 0.5 m.

1.2 In the area of the plan where the representation of the HQ has been adopted for information only, terrain elevations of private building plots up to 31 m above sea level (NN) must be made so that the height of the finished ground floor level lies above 31 m above NN. The elevation must be made with material suitable for the infiltration of surface water.

1.3 The eaves height of the buildings, measured from the top edge of the finished ground floor level to the intersection of the outer edge of the rising masonry with the roof covering, must not be lower or higher than the following values: - for a roof pitch under 30°: min. 4.00 m up to max. 5.80 m - for a roof pitch over 30°: max. 4.00 m

1.4 The maximum building height (ridge height), measured from the top edge of the finished ground floor level to the top edge of the ridge (highest point of the roof covering), must not exceed 9.00 m.

The narrow hallway on the upper floor. What do you want to put in there? A cleaning supplies cabinet is too deep.

In the northeast children's room, you will need light much more often. It is too dark for homework in daylight on some afternoons.

Ah, the dining area is intended as a good living room. I stick to a reasonable eat-in kitchen without a makeshift solution on the kitchen line.

The grandparents are supposed to check on the children sometimes. Whether in the evening, after school, or if the child is sick. Also, the grandparents will sometimes need a bit of help. Do you really want to go out in wind and weather? There are even multi-generation houses that have a planned communal area. Whether you want the latter is up to you—it certainly has its advantages. A connecting door is a must and not a restriction on privacy.

The storage room on the upper floor is 1.35 meters wide and up to the 2-meter line 3.50 meters long.
I do think quite a lot fits in there.
Suitcases, vacuum cleaner, cleaning supplies.

And regarding the entrances, I really see it differently. A connecting door is an absolute no-go…. What speaks against simply leaving the front door, walking the 6 meters across the covered area?

Do you really want to go out in any kind of weather?

Why not? You can manage those few meters. I wouldn’t build an indoor connection either.

the storage room on the upper floor is 1.35 wide and 3.50 long up to the 2-meter line. I do think quite a lot fits in there. Suitcases, vacuum cleaner, cleaning supplies.

A lot fits in there, yes. But whether it can be carried out again is another matter. ;) It will work, but it’s not easy to carry a bulky item like a decorative box or suitcase past a cleaning shelf.

The kitchen can certainly be the heart of a house. It should be. But here it isn’t; it’s a passage room, more like a traffic area.
As the builder, I would be here with my plan exactly for this reason—to find out just that (because I hadn’t seen it myself) and to take the reins and change something again with a new design where the kitchen is exactly what you want: a central meeting point.