He was director of the National Museum in Warsaw in the years 1935-1985, deputy to Sejm - the Polish Parliament (1965–69), and an UNESCO expert for the protection of monuments and historic sites.
In 1924 he defended his doctoral thesis (a monograph of Ephraim Szreger - Warsaw architect of the Age of Enlightenment).
He was a member of several governmental departments and commissions related to art conservation and was also a deputy to Polish Sejm (1965–1969).
He was a UNESCO expert on Polish and international cultural heritage, highly active in the restoration of the Royal Castle, Warsaw and Old Town in Havana, Cuba.
Lorentz conducted an intensive correspondence with Lithuanian art conservation specialist Vladas Drėma.