No, I sometimes get things mixed up too ;)
and the building envelope from the site plan measures approximately 15x17m – right?
The site plan and the measurements should already be correctly known here. A tricky plot with jack-of-all-trades wishes to draw on it, actually a thing where later you cannot even take away half a meter. Conversely, you can juggle walls for thirty hours and it still only fits 70%, so basically a draft for the bin.
That also surprises me about the statement with 3 meters on the left and right when I, as a layperson, see 4 and 6 meters that need to be observed.
Regarding the questionnaire on page 7: it surprises me that there is actually no room program, but rather I have the feeling that you described the house from the general contractor.
For example: shouldn’t it be left open whether the attic floor is needed at all?
Are there already restrictions or wishes for the residents of the granny flat?
Do you like sun? How is the daily routine? What is the balcony for? Are you excluded from your north garden? No island in the kitchen?
I often miss the “why”!
Yes, as I said: I have already started here, despite the vague property description. Simply because I feel like it. However, my willingness to implement is of course limited if the plot is not even clear yet. I would post it here purely as a train of thought*, to also illustrate some difficulties that come with orientation plus granny flat plus restricted building envelope. And exactly *for that reason rather on a different level than an open forum, because here many sketches are seen as finished – without considering the difficulties. ;)
One example: at the expense of a nice open space, it could be that a guest WC does not get a window. If you try otherwise, only other crap comes out. In that respect, I would tolerate that regarding the open space, but not everything else. However, it is also not constructive.