Wet Areas tiling have to be dony builder so we to take away the wet areas from 165M2
Laundry = 4.8128 square meter
Powder room inc shower = 4.215 square meter
Total Wet areas = 4.8128+4.215 = 9.03
Logically ground floor area exc wet areas should be 165.6 - 9.03 = 156.5 square meter
I measured myself it is around about 135 M2 , bit worried. I dont know how they measure it.