The Wales Millennium Centre is a world-class arts centre and an icon for Cardiff. The 33,000m2 venue provides a base for seven cultural organisations, including the Welsh National Opera.
The focal point of the building is an 1852-seat theatre designed to stage both opera and amplified musical productions. Accommodation also includes rehearsal rooms, a studio theatre, dance studios and a recording studio.
Arup provided a wide range of services to achieve the architectural vision for the centre. These included structural, civil, mechanical, electrical and public health engineering as well as planning supervision, infrastructure, geotechnics, transport planning, fire safety design, acoustic and theatre consulting.
The auditorium was designed to be equally excellent for opera and amplified sound. Innovative acoustic design included 'auralisation' – a technique allowing the client and design team to listen to simulated performances in the auditorium during the design. This analysis assisted in the elimination of sound pollution from a nearby road tunnel, delivering significant cost and programme savings.
Savings in time, cost and energy
Arup employed a unique approach to the building programme, planning for construction from the inside out. The choice of a steel frame for the auditorium enabled an early start to construction while the architect and acoustician continued to develop designs for the inside.
This approach also achieved a weather-tight auditorium enclosure quickly. The construction of the 'shell' roof and interior finishes and services of the auditorium were then completed simultaneously. The steel frame also resulted in a much lighter structure with low-cost foundations.
The theatre is an acoustical triumph, with wonderfully clear, balanced sound... every voice audible, the words as clear as can be, the instruments both blended and distinct... ”
Designed for flexibility
Careful development of the walls, balcony and the sculpted ceiling of the Donald Gordon Theatre help sound to reach every seat in the auditorium. The theatre is designed to provide excellent lines of sight from each of the 1852 seats.
The orchestra pit is designed to be flexible. Elevators enable the floor to be configured to accommodate different sizes of orchestra and to provide additional audience seating when smaller orchestras are performing. Acoustic flexibility is provided in the form of movable surfaces that can be sound reflecting, sound absorbing or acoustically transparent as necessary.
Unique solutions have been found to the acoustic and aesthetic requirements of the music spaces. Sound reflection and scattering properties are achieved through materials and forms sensitively integrated into the internal architecture.
The acoustics of the Donald Gordon Theatre can be altered using motorised sound-absorbing curtains and sliding sound-absorbing panels. This variable sound absorption system has been integrated into the interior design through a selection of sound transparent facing material similar to the seat upholstery. When fully extended this system provides excellent conditions for performances with amplified sound.
Internal sound insulation
Sound generated in the foyer and concourse is absorbed by the lobbies and inner foyers that wrap around the theatre. Noise from outside the building is eliminated by the double roof construction. The ventilation for the theatre is designed to be silent and draught free.
External sound insulation
The design team suspected that the auditorium would require isolation from noise generated by a nearby road tunnel. The acoustics team developed a vibration measurement system and used SoundLab, Arup’s purpose-built listening environment, to simulate music in the presence of the predicted levels of acoustic interruption. This analysis revealed that the building need not be isolated – delivering significant cost and time savings.