9 Conduit Street, Mayfair, London: the stairs to the library

NOTES: This was the headquarters of the Royal Institute of British Architects from 1860 until 1934. The building was originally designed by James Wyatt in 1799. But was subsequently added during the RIBA's tenure from 1859-1934. Three top-lit galleries were added in 1859 by Charles Gray and J. Edmeston Junior, of which one remains which has a ribbed and glazed barrel vault. The rear first-floor room is a top-lit creation by Macvicar Anderson of 1879 and the square meeting room with dome was added in 1924 by Arthur Keen on a concrete frame devised by Oscar Faber.