The three-year building program has replaced 40 year-old buildings and delivered new restaurants, office and retail to Cloisters, a key thoroughfare.
Brian Dixon, executive officer and diocesan secretary for property owner the Anglican Diocese of Perth, said the work had brought a modern, vibrant environment into the city while also improving the pedestrian network.
"The redevelopment has already completely revitalised and transformed the site," Mr Dixon said.
Work began with the redevelopment of the building at 861-863 Hay Street into a nine storey office building designed by Buchan Group.
The refurbishment also included widening and realignment work to provide a consistent thoroughfare for pedestrians up Mill Street, through Cloisters arcade and along Shafto Lane to Murray Street.
The upgrade included more than 2000sqm of retail space which was leased by Lease Equity and includes the new Chophouse restaurant on St Georges Terrace.
The former open brick courtyard in Cloisters is now glass-enclosed with a retractable, glazed roof that has become a popular daytime social hub for CBD workers.
Beck Advisory, which acts as development adviser for the Perth Diocesan Trustees, said the work allowed the site to reach its potential.
"The Perth Anglican Diocese commenced planning for this project at the right time," Beck Advisory director Hamish Beck said.
"The revitalised Cloisters has an excellent tenant mix and the introduction of the Chophouse along St Georges Terrace is a major draw card for the development."
The Cloisters, built in 1858 and in front of the Cloisters site on St Georges Terrace, remained untouched during the redevelopment.