It is hoped the Sydney Opera House’s sound problems will be a thing of the past after a much-needed acoustic upgrade is rolled out during a $245 million revamp.

The ageing venue’s undercover entrance will also be transformed and the carpark there scrapped, giant digital screens installed and the box office and foyer given a sleek makeover, it was revealed.

The Opera House and NSW government unveiled working designs for the 43-year-old building’s largest ever public works program on Thursday.

Sydney Opera House chief executive Louise Herron said the project includes a new function room, a dedicated space for children, better wheelchair access and new theatre technology.

The renewal plans, Ms Herron said, were needed to make the world-famous building more accessible and to update old technology.

“They’re essential for the Opera House to serve future generations as well, or even better, than it has since opening,” she said.

Actor John Malkovich once reportedly described the acoustics at the Opera House as “hideous”.

The acoustics, accessibility and efficiency of the concert hall will be upgraded. Photo: Sydney Opera House

On Thursday, Sydney Symphony Orchestra chief conductor David Anderson likened sound quality in the concert hall to images taken by the early Hubble Space Telescope: “breathtaking images and very inspiring, but nothing like the fix that happened when they actually got the mirror focused”.

Ms Herron said the Opera House had engaged leading world experts to improve the hall’s acoustic performance.

The NSW government has kicked in $202 million while the Opera House will contribute $43.5 million of its own funds to upgrade its Joan Sutherland Theatre.

A premium function centre will be built on the periphery of the building. Photo: Sydney Opera House

Work will begin next May, with the biggest disruption expected in mid-2019 when the concert hall is due to close for 18 months.

The entire project is estimated to be completed by early 2021.

NSW Opposition arts spokesman Walt Secord complained that western Sydney was not getting its share of $600 million allocated to arts infrastructure.

“Unfortunately, there is a massive funding imbalance towards Sydney’s east with western Sydney arts receiving very little,” he said in a statement.

HIGHLIGHTS OF THE NEW OPERA HOUSE

• New acoustic ceiling and reflectors to improve sound in concert hall
• Northern marquee to make way for an 190-seat function centre
• Revamped, sleeker box office and foyer
• Giant digital screens to display art or other images at the undercover entrance
• Creative learning centre dedicated to children, with workshops and play activities
• New theatre equipment to replace ageing technology

-AAP