This file contains the digital vector boundaries for built-up areas in England and Wales as at 27 March 2011 (Census day). The built-up area boundaries are generalised and created using an automated approach based on a 50m grid squares.
UPDATE - 22/06/2017 - This boundary set has been updated with a new field (URBANBUA) describing whether the BUA has a population of 10000 or more (2011 Census) usual residents. No boundaries have been altered.