Narrow plot and fencing - assistance

But in the end, you have to say, new development area, 437sqm, privacy is something else.

With 437sqm you will always have at least 3m distance areas on all sides, ... That means about 50% of the plot area are distance areas, another 25% is made up by the house.

I see it the same way. Privacy and seclusion are in a proportional relationship to the size of the plot. With 437sqm rather difficult, with 3,000sqm or even 6,000sqm rather a matter of course. Moreover, 80cm height in the "privacy screen" is not really efficient. And a hedge does not protect against (unwanted) eavesdropping by the neighbors....

on the south side (field path) possibly as well

The "possibly" is crucial for your wishes. If only 80cm are allowed there as well, the property is unsuitable for you. If not, you still have your private cozy corner as a living room extension behind the house (SE) – the distance to the boundary is at least 5.5m – and a large garden next to it (SW) to look at and play in.