South and west will not be developed in the next few years. Only, what costs are to be expected... because the slope is partly quite steep and the building window is limited, etc...
Yes, I can't say much more than that based on this limited information. My favorites would probably be 16 to 18, 9, or 23. The series from 18 to 23 takes a step of about two meters in height from one plot to the next, so reference heights would be interesting – from my perspective, it would be best to have a fixed one specific to each plot.