At the heart of Great Hall is the auditorium. A moveable acoustic wall and adjustable flooring enable the space to operate as a 320-seat theatre (with substantial foyer space to the rear), an assembly or lecture hall for the full school (over 600 staff and pupils), or as an open hall for dances and receptions. State of the art LED lighting can switch from an intimate and exciting theatrical mood to exam hall conditions at the touch of a button.

As a teaching theatre, safety is a key consideration, and the inclusion of a tension wire grid over the auditorium is a major innovation. This enables technicians to set and focus lights without resorting to tall ladders or scaffold towers. The theatres are served by spacious control rooms to allow plenty of room for pupils to hone their technical skills. Wherever possible, these technical areas are fully accessible. Beyond the stage lies a fully equipped workshop, technical stores, dressing rooms, changing areas and a green room.