1913: Addition of new wing to One Birdcage Walk

The Institution's move to London in 1899 resulted in rapid growth in the membership and when the site of the pub the Storey's Gate Tavern became available in 1911 the Institution purchased the land with a view to building an extension to One Birdcage Walk.

The new wing was designed by architect James Miller who had also designed the neighbouring building for the Institution of Civil Engineers (ICE).

Work was completed by 15 November 1913, but there was no grand opening as there had been for the main building.