Ciao Sandro I'm not an expert at all, but as there is no answer from others and after seeing your picture I would not make a vertical loop that way. In my opinion it will be too close to the terrace
Hi Mauro, with this dimensions the antenna impedance will be mainly determined by the loss resistance. For a loop circumference of 20m and a 2 turn loop the copper resistance will be about 0.13 Ohm.