Records 1908 to about 1972.
Some important items from this period are in the second volume of the BNA Archives. See the inventory on that volume. They are:
- The annual reports, statutes and by-laws of the BNA beginning in 1919;
- Honorary members, 1898-1955 [1964];
- membership lists of the Society and of the BNA, from the founding of the Society (1842);
- some documents relating to the Circles, 1878-1940;
- various contracts 1937-1957;
- the Housing Architecture Core Group from 1959 (there are also documents in this first volume);
- documents relating to the PPC (Permanent Competition Committee), 1914-1974.  NB Probably documents from the PPC to the BNA, and not the archives of the PPC.
- The Training Council of the BNA 1947-1968 (also documents in this first volume);
- UIA (Union Internationale des Architectes), from 1953 (also documents in this first volume).