Arrangement house and parking spaces - small plot - house with a granny flat

I find the plot of land completely unsuitable for the project, as it is far too small. Even by Munich standards, 340 sqm for a single-family home is already little, but then with a granny flat and the associated parking spaces? Is the granny flat intended to be permanently occupied? For me, that would not be any kind of living quality, the little garden space is almost entirely taken up by parking spots. And as has already been said, whether they would be approved like that would have to be clarified first and foremost.

Otherwise, I see the parents completely on the ground floor including HAR and stairwell, bedrooms + sanitary facilities on the first floor, common room + roof terrace as desired in the attic.

But that is already 2 full floors plus attic. Now we are missing a few statements from the OP regarding size proportions of the EL apartment, etc.

But those are already 2 full floors plus an attic floor.

Yes, if the OP writes at the beginning that 2 full floors are allowed, I would believe that at first. But you are right, without the exact development plan, you can't get any further here.
But please do not link. That is prohibited here under penalty. Maybe that is why he already has a ban and cannot respond...

The question about the slope has not really been answered. Without a development plan, there is little to say here.

Budget?

Please clarify whether the [CP] should also adhere to the 5.5 m.

No matter what the development plan says, I simply cannot see an in-law apartment on 340sqm, and I say this as someone who built on a 300sqm plot! We were only able to realize the project with a setback area transfer from my parents. The "garden" is really tiny then. The terrace is only 3m deep. The light well also takes up space, and the rest goes to the parking area for the heat pump, the driveway, and the garage. Bam, you've built on 210 of 300sqm.

No matter what the development plan says, I simply cannot see an accessory apartment on 340 sqm, and I say that as someone who built on a 300 sqm plot!

Such blanket statements are, in my opinion, nonsense, since apparently you can build upwards here. You could then just call it a two-family house, I agree with you there. But I wouldn't say it's not possible at all. The question remains whether it is desirable.