When James Stevens, the head of global real estate at Aviva, said the institutional investors’ latest completed project was one of the most complicated ever to be done in the City of London he was not exaggerating. The quest to extract ever more value from some of the most expensive development land in the world means project teams are devising ever more radical solutions. In congested cities, underground infrastructure is inevitable but the project team on One Liverpool Street were faced with an extreme situation. 

The site was situated on the corner of Liverpool and Blomfield Streets, with the District line passing through an open cutting in the middle of the site, a Royal Mail tunnel below this and the Elizabeth line below that. The Elizabeth line Broadgate ticket hall is situated under the north-east corner and a seven-storey high Elizabeth line vent shaft occupies the space to the south of this. And a utility corridor filled with power and data cables passes under the pavement next to the site.