Please provide tips for designing the ground floor plan

Show me please what you mean. [ATTACH alt="Layout.JPG"]41708[/ATTACH]

It probably means: From the view from the street, make your house wider, but a bit less deep (=larger garden at the back). The rectangular shape causes a longitudinal axis in a north-south orientation, if this is a requirement of the development plan (?).

Typo: East-West direction like the arrow direction

Okay, do you have an excerpt from the development plan or can you quote the part with the East-West axis?

Position of the structures (§ 9 para. 1 no. 2 [Baugesetzbuch]) In the general residential area, the longitudinal axis of the main buildings is to be oriented basically in an east-west direction, according to the graphic determinations for the respective quarters. Deviations from these axes are permitted up to an extent of 20 degrees if this allows for more efficient use of solar energy.

In the general residential area, the longitudinal axis of the main buildings is basically to be aligned in an east-west direction,....

I am not very familiar with public building law.
It would be a question for the experts:
Is the longitudinal axis of the building determined by the external dimensions?
Or by the ridge direction?
If the latter applies, then perhaps a gable roof with an east-west ridge direction would be possible, even if the house has smaller dimensions in the east-west direction than in the north-south direction....

Please show me what you mean.

I was just about to say that as well

Is the longitudinal axis of the building determined by the external dimensions?
Or by the ridge direction?

One should expect it to be specified in the text part.

One should be able to expect a provision in the text part.

Is there no universally valid definition for the term longitudinal orientation if there is no provision in the text part?