The recent completion of Network Rail’s new western concourse at King’s Cross station is the culmination of over 12 years of above and below ground station modernisation work that has transformed rail transport links in this part of north London, UK. The new concourse has been constructed directly above London Underground’s northern ticket hall, which was the second and last phase of the redevelopment of its King’s Cross St Pancras station. The construction of the northern ticket hall was a major undertaking and ultimately provided the support structure for the western concourse. The new ticket hall greatly enhances the overall capacity of the underground station and provides a second means of access to the Northern, Piccadilly and Victoria lines while also incorporating below ground links to both the King’s Cross and St Pancras main line stations and to the enlarged Tube ticket hall. This paper describes the overall construction methodology of the main box forming the ticket hall with particular reference to the techniques used for bulk excavation, installation of plunge columns and the use of temporary propping.