In 1999, after more than 30 years, there was reconciliation with the Sydney Opera House which resulted in Utzon submitting his Design Principles booklet to the Sydney Opera House Trust in 2002. He noted that ‘luckily Ove Arup stayed on the job; otherwise it would never have been completed. He acknowledged that ‘the Opera House today is of course not my or our building, it is as much a building made by Hall, Todd & Littlemore'.
Utzon stated that he wanted the Australian architect Richard Johnson to work on any modifications and consequently, they collaborated on The Colonnade, the Accessibility and Western Foyers Project, and the concept designs for the Opera Theatre Renewal Project.
After more than 30 years, the Sydney Opera House had its first interior designed by Utzon in collaboration with his son Jan Utzon and Richard Johnson. The Utzon Room, a transformed reception hall that brings to life Jørn Utzon's original vision for his masterpiece, was officially opened on September 2004.
In 2003, Opera House executives indicated that the long-term plan for the redesigned opera hall was to restore the Curtain of the Sun to the proscenium arch.