Superseded — the reference text is now D.P.R. 380/2001. A repealed text may still apply in transition: check the dates before using it.
Law 64 of 2 February 1974 is the mother act of modern Italian seismic regulation: it made technical rules mandatory for all buildings, with special requirements for seismic zones, and delegated their periodic update to ministerial decrees (the series leading to today's NTC). Published in Official Gazette No. 76 of 21 March 1974, in force from 5 April 1974, it was almost entirely repealed by Article 136 of Presidential Decree 380/2001 with effect from 30 June 2003: its framework lives on in Part II of the consolidated act and in the NTC. It remains the period reference for buildings designed between 1974 and 2003.
All buildings, with reinforced requirements in municipalities classified as seismic, during 1974–2003.