The existing auditorium, designed by Charles Barry and built during 1858, is Grade I Listed and has been faithfully refurbished to preserve its essential character. It maintains an intimate relationship between the stage performers and the audience resulting from its spatial proportions, ie the form of the balcony fronts and their relationships to the proscenium and outer walls, the domed ceiling and its lighting and decorative elements. All these factors transcend its shortcomings.
However, extensive interventions and repairs have been necessary to improve sightlines, acoustic performance, audience comfort, access, audience facilities, seating capacity and theatrical lighting.
An improvement in sightlines and seating results from re-raking the stalls and balconies, especially at the sides, re-aligning the boxes at the grand tier and balcony in order to view the stage rather than the audience, and extending the amphitheatre. Additional seats have been placed centrally at the back of the grand tier, balcony and amphitheatre and new standing places have been created at the lower slips.
Acoustic performance in the old house was generally considered to be good. However, improvements to sightlines have resulted in acoustic benefits through maximising volume. Performance is further improved by adjusting materials to reduce absorbency, eg wood floors replace carpet, and extraneous noise is controlled by insulating the roof and structure and forming separation lobbies to foyers and staircases.
In the old house environmental control was poor. Now air cooling has been introduced through a displacement system to minimise ventilation noise. Air enters below the seats via ventilation plenums within the floor structures and is extracted through the occulus in the dome. To reach the plenums, supply ductwork is threaded from the roofspace downwards through cellular brick structures that are surrounding the horseshoe.
The hierarchical nature of entry to the auditorium has been eliminated. In the old house access to the stalls and lower balconies was through the porte cochere along Bow Street, but the poor relations entered by an innocuous side stair from Floral Street. It was an inverted 'upstairs downstairs' arrangement.
Now the audience maintains a common and egalitarian entry through the porte cochere and foyers. New stairs, lifts and wcs serve each level and are accommodated between the inner horseshoe and outer walls. Wheelchair users access each level except for the stalls.
The redecoration strategy re-establishes the essential character of the much-loved auditorium. Royal Opera House red predominates in the fabric of the new seats, balcony fingerboards, striped wallpaper, carpets and ceiling soffits.
The dome, balcony fronts and proscenium arch are selectively gilded with extensive surfaces of light blue and ivory. Unlike the Garnier, only highlights of the mouldings are gilded. The floors are dark oak and the partitions a rich walnut.
In contrast, the flytower and stage are formed from a new industrial construction built as a steel frame behind the retained historical facade to Floral Street. The galleried flytower, three times the height of the proscenium arch at some 42m, accommodates scenery flying sets and lighting bars, and is isolated from the side and rear stages by massive steel acoustic and fire doors, each weighing in the order of 60 tonnes.
To its rear and side the space extends as an unobstructed three-storey volume from Russell to Floral Street. The generating principle is that sets for six productions can be erected, retained and moved on automatic stage wagons and compensating elevators throughout this space. Thus it reduces the effect of an inexorable, labour-intensive process of erecting and dismantling sets for individual productions.
These spaces - rarely to be seen by the general public - contrast dramatically with the auditorium both in volume and aesthetic treatment. This is opera as factory.