Model; Westminster underground station (Scheme G), by Three Dimensional Developments Ltd, circa 1995

The new Parlimentary Building and the proposed interchange with the new Jubilee Line provided an opportunity for a thorough reorganisation of the site. The ticket hall has been relocated below ground level and the courtyard of the new building has covered the District and Circle Line tracks, reducing noise and vibration. Because of the work on the New Parliamentary Building and the need to keep the existing District and Circle trains running, the construction of the Jubilee Line tunnels and platforms was a particularly difficult engineering project. 17 escalators serve the station which extends to a depth of 40 metres. Due to the close proximity of Big Ben, Westminster is the only station on the 16 kilometre Jubilee Line extension where East and West tunnels are on top of each other instead of being side by side.