The $150-million renovations to the Sydney Opera House’s Concert Hall were revealed this year, being the final project in the Opera House’s ‘Decade of Renewal’ capital works program valued at nearly $300 million.
The Concert Hall’s upgrade, completed in time for the 50th anniversary of the Opera House in 2023, was carried out by a team lead by ARM Architecture and Arup.
The project, which closed for the renovations in February 2020, reopened this July with the first performance in the upgraded Concert Hall being Mahler’s Resurrection symphony, performed by the Sydney Symphony Orchestra.
Sydney Opera House Chief Executive Louise Herron AM said artists and audiences were set to experience world-class acoustics in a venue that is more accessible, safer, and better equipped to present the full breadth of 21st-century performance.
She said: “It’s hard to describe what an exciting moment this is for us.
“Musicians across the world dream of playing here, but all too often the experience has fallen short of expectations – with this upgrade, we have corrected that imbalance.”
Following the $71-million renewal of the Joan Sutherland Theatre, which was completed in 2017, the Concert Hall renovation project improves the venue’s acoustic performance, accessibility, and its staging systems.
With 2,600 seats and measuring 45 metres long, the Concert Hall is one of the largest and longest performance theatres in the world, creating technical challenges for acousticians in refining the sound amplification of the space.
At nearly 50 years old the Concert Hall was faced with end-of-life theatre machinery above the ceiling, a poor reputation for acoustics and mobility issues that plagued the whole of the building with significant spaces only accessible by imposing staircases.
ARM Architecture Principal Andrew Hayne explained the project had three main goals: “First and foremost, the goal was to improve the acoustics of the concert hall.
“Second, it was to improve the functionality of the room itself, to be able to cater to different types of performances and to make changes between performances less human dependent and more automated.”
This was done by implementing new theatre machinery and flying equipment overstage which also enhanced the diversity of show types that could be performed. The new technical overlay also vastly improves the changeover times between show types.
“And the third made it more accessible to people – because it’s clearly built in a different era when accessibility wasn’t on the cards.”
This was achieved by providing a new passageway through the eastern foyer staircase, leading to a new lift connecting all levels of the northern foyer (which looks out over Sydney Harbour) and the circle and upper circle of the Concert Hall.
Hayne added that renewing the building’s heritage fabric had been a fraught process, requiring substantial research to ensure the original architects’ intent was preserved.
He explained: “We dove deep into the history of the place, getting to know and understand Utzon’s original design approach, but also importantly, the work of Peter Hall who took over once Utzon left and has been unfairly maligned over the years.
“It was primarily his work that we were interacting with and so understanding the background and design intent of his elements was critical to the success of the new interventions we have made.”
Modern stage and sound design
The hall’s acoustics were upgraded by replacing the original hanging reflectors with 18 petal-shaped fibreglass reflectors, which are designed to improve acoustics for the audience as well as performers, and finished in a magenta colour that references the original seat fabric colour introduced by Peter Hall.
Hayne said these were vital due to the poor acoustics resulting from the high ceiling and the hall being at least one third longer than what an ideal concert hall should be.
He continued: “These two factors meant that acoustic energy from the orchestra was getting lost in the upper reaches of the ceiling and would also not make its way to the very back of the hall.
“There are 12 vocal petals above the orchestra specifically for the musicians themselves, to reflect that early energy to them so they can hear each other and themselves.
“Then there are four larger petals in front that will be angled in the direction of the audience, and it’s largely their role to push the sound energy up and to the ends of the hall.
“There are also two at the south end that are designed to reflect energy for the choir.”
The petals are complemented by other acoustic detailing, including carved timber panels across the stage and stalls.
Made from the same brushbox timber that is already present in the Hall, the timber panels diffuse the sound, preventing any direct reflections and therefore create a blended sound and a sense of envelopment in the music.
“Designed with the idea of visually capturing sound, the panels consist of three overlapping sound waves frozen in time.
“The result is a highly tactile and sculptural surface that encourages the hand to run along them.”
There are also a series of Operable Wall Reflectors (OWR) which deploy from the side walls of the ceiling which have been cut into the original timber and retain the original timber front when closed. These provide lateral reflections to both the performers on stage as well as the audience through the stalls and the circle.
Upgrades to the stage meant it had to be completely rebuilt to accommodate the installation of automated stage risers weighing a total of 95 tonnes, and deployed by the touch of a button. This enabled a tiered layout for orchestral performances, as well as lowering the stage by 400mm to improve audience sightlines and the acoustic connection between different orchestral sections.
The final series of acoustic interventions included automated drapes that deploy from the ‘crown’ over the stage, the upper side walls of the ceiling as well as from the box fronts adjacent the stalls. They are hidden when not in use and are again deployed at the touch of a button via the new stage automation system.
“In an amplified performance addition absorption is required to lower the reverberation time in the room. Previously these were added in an ad-hoc and undesigned fashion taking the stage techs a long time to deploy and involved much manual handling. At the Hall, the ‘amplified mode’ is now a resolved design outcome, one that is more befitting of the room.”
The overhaul also included a new passageway through the eastern foyer, as well as lifts connecting all levels of the northern foyer, circle, and upper circle. Previously, 50 risers in two flights of stairs had to be climbed to access these areas.
Furthermore, the new lifts allow wheelchair users to access these areas for the first time, with Hayne noting this was particularly important for the northern foyer which overlooks Sydney Harbour.
“The introduction of the new passageway and lift in the northern foyer transform the visitor experience for people with mobility issues.
“This brings equity in access to what is one of the most picturesque spots in the SOH with a fantastic view out over the Harbour.”
NSW Minister for the Arts Ben Franklin said the concert hall was the beating heart of the Opera House.
Franklin added: “The NSW government is proud to have supported this important project, which will secure our nation’s most significant cultural icon for the next generation, with a positive and lasting impact on the community for years to come.”
The Concert Hall’s renewal involved the installation of 174 tonnes structural steel and 70 tonnes reinforcing steel, with a quarter of the new structural steel coated in hot pink paint to distinguish it from the primary steel that supports the building.
Nearly 45 tonnes of birdcage scaffolding was erected by the builders in order to reach the ceiling, while more than 9,000 square metres of protection was installed across the Concert Hall and its surrounds to safeguard the heritage finishes.
In line with modern sustainability practices, more than 91 per cent of demolition waste was recycled, far exceeding the target.