Renovations for the improved safety of pedestrians at the Sydney Opera House began on Tuesday, with the NSW government calling for expressions of interest on the project.

Accidents occur at the iconic landmark almost everyday and many of which involved tourists being hit by vehicles on the site's forecourt.

A $152-million upgrade has been announced by the government, which on Tuesday called for expressions of interest for the Vehicle Access and Pedestrian Safety Project.

A new tunnel will be built from the northern end of Macquarie Street to a new underground loading dock, which will divert delivery vehicles underneath the forecourt.

"We are improving visitor and worker safety," said Acting Minister for the Arts Linda Burney.

"And offering a revitalised visitor experience of Jorn Utzon's 20th century architectural masterpiece, befitting its status as a World Heritage listed icon."

A new scenery platform is also set to be built underground for loading and unloading sets.

Other tunnels will be constructed that will connect the loading dock to new lifts for food and drink deliveries.

Bennelong Drain, a stormwater drain servicing northern parts of the CBD, is being diverted.

The Opera House brings in around 7.4 million visitors every year, and over 1000 vehicles a week drive past the forecourt.

Ms Burney said the project would support 500 jobs.

Work is scheduled to start in early 2011 and finish by 2013. The Opera House will remain open during the refurbishments.

"The call for expressions of interest marks the beginning of the largest construction project on site since it opened in October 1973," Ms Burney said in a statement on Tuesday.