Bernasconi was born in 1726 in Castel San Pietro, a settlement near Lugano in Switzerland's Italian-speaking Ticino canton.
[2] The area, and the Bernasconi family in particular, had produced numerous artists and architects, active across Europe, in England, Spain, Italy and Germany, as well as several distant cousins who had also come to work in Russia.
[3] Antonio was a descendant of the prominent stuccoist Pietro Magno, who decorated many palaces and ecclesiastical buildings in central Germany.
[5] He later worked at the Pavlovsk Palaces, but in 1785, was forced to resign from his position due to ill health occasioned by the damp conditions by the Gulf of Finland.
He recommended his countryman Felice Lamoni of Muzzano for his replacement, and returned to his homeland, accompanied by his wife Elisabetta Fritz and son Giuseppe Bernasconi (born 1778).