Studiodare was lead architect for the Northern line extension Transport & Works Act Order application; this built on previous roles as architectural lead on the project. The project was led by Halcrow CHM2Hill and the client was Transport for London. Our brief was for two new stations and associated midline vent shafts. In contrast to many sub-surface railway systems, which are generally only remarked upon when they fail to function, we sought to create meaningful and enjoyable public places. In addition we prioritised clear passenger movement and effective operation by TfL. Our scope included the coordination of architectural design with all engineering disciplines; coordination with tunnelling engineers over station locations; and option workshops with TfL. Ultimately, we produced the architectural package for the TWAO report and Public Enquiry. When complete, the Northern line extension will provide a new 3km branch of the line from Kennington Station to a new station at Battersea Power Station; there will be a midline station, Nine Elms, on Wandsworth Road. The transport link is vital for the area and for the increased demand from planned developments in the surrounding Opportunity Area: 195 hectares of former industrial land earmarked for redevelopment.