Rough construction plan draft for a single-family house including double garage and entrance

Site coverage index: individual Floor area ratio: 2.5

You misunderstood that. The floor area ratio is not the number of floors, but the factor by which the plot area is multiplied to determine the maximum living space. For example, floor area ratio "0.4" x 636 = 254.4 sqm. The site coverage index indicates the same for the footprint of the house, e.g. site coverage index "0.2" x 636 = 127.2 sqm. There have been more and more development plans recently that specify only the site coverage index or floor area ratio, because this is practically sufficient in connection with the maximum number of floors.

Here is the exterior view.

Your window lintels are clearly below the door lintels. That looks stupid, and you also get a stupid view from there ;-) But — even though I still see "a lot of potential" in your floor plans — the discipline in the number of different window formats already appeals to me. Dimension lines are, let’s say, "not your strong point," and you apparently have not yet dealt with construction dimensioning.

The views are only meant to illustrate ... the program simply allows it and is fun in 3D as well as in draft mode ;)

Sebastian, the floor area ratio cannot be individual. Although Bavaria is always somewhat different, if you write "rural," I doubt you are allowed to build over so much land. Check this best with the floor area ratio and plot ratio before you put in more effort. Otherwise, the balcony could be better used by the granny flat. An external connection between the parents' and children's rooms is not sensible. If, for example, the room doors in the granny flat are initially repositioned, it could actually become nice with a sunny balcony.

Otherwise, I would basically first open up the main house to the south.

Okay :) So I marked south wrong. South is on the balcony side :) I can't find anything about the floor area ratio or similar. I just drew the plan according to my wishes. It is completely clear to me that an architect and structural engineer have to review and revise everything. Our development plan is from 1996 at the latest, and a lot of new construction is currently happening around us. These new buildings are anything but according to the development plan. What I have already learned from the municipality is that I am allowed to build 2.5 stories high and the ridge direction does not matter. I'll attach the development plan for you. Please don't stone me. I am an amateur and just trying to get help and advice through a forum like this. I will only build once in my life, and I want to make sure this huge sum is well invested and that I build according to my rough ideas. Best regards Sebastian

Dimension lines are, let's say, "not your master question," and you obviously haven't dealt with construction dimensions yet.

No, that is not my "master question" :) As I said, I just sketched the whole thing without any structural analysis or anything like that. Here it's purely about the floor plan, and yes, the windows and doors obviously play a role in that :)

I cannot find anything about floor area ratio or similar.

06.jpg: Floor area ratio 0.4, plot ratio 0.8

These new buildings are anything but according to the development plan.

Can you assess that or has it already been acknowledged by the municipality?

What I was able to learn from the municipality is that I am allowed to build 2.5 stories high

Did the official really talk about half floors? These do not exist in building law. For your property, an attic expansion also does not seem to be permitted (II and not II+D).

and the orientation does not matter.

02.jpg: item 0.3.1; but your plan does not contradict that You should definitely draw your property to scale (obtain and enlarge a cadastral map or use BayernAtlas) and transfer the building boundaries to it to scale. It seems to me that your house does not fit into the building envelope, so all your efforts might be pointless. Also note that the house must maintain at least 3m distance from the boundary.

The floor area ratio is 0.4 The floor space index is 1.1 Our plot currently has a total area of 1790 sqm on which a house already stands. This is to be divided later into 636 sqm and 1154 sqm. Can I currently use the 1790 sqm as the basis for calculation or must I assume the later divided plot?