It will follow a 12 stage 'test/hold' process, where each stage must be approved by Cera before work commences.
Today, Bishop Barry Jones welcomed the staging process as a positive way to move forward ensuring the best future for the cathedral.
"I am delighted to announce today that I can move forward with recovery plans for the Cathedral and all parishes," he said.
"Cera's commissioning of works gives the certainty needed to begin the major programme of work to repair, rebuild and strengthen those buildings impacted by the Christchurch earthquakes."
Detailed engineering assessments focussed on the retention of the nave will commence later this year.
Lance Ryan, chairman of the Cathedral Management Board says that stage one, which is expected to take 12 months, will mostly consist of clearing the areas around the nave so a fuller investigation can be carried out on the ground underneath.
"Depending on the outcome of those studies, we very much hope that the beautiful nave can be saved," he said.
Costs to deconstruct the badly damaged surrounds and to restore and rebuild the nave and associated sections are capped at $45m. The diocese is seeking to fundraise $15m in support of the plan.
Keith Beal, property and development manager for the diocese, said the move means that in addition to a number of smaller schemes already underway across the diocese, some of the larger and more complex ones will now commence.
"This is a significant decision," he said.
The church today acknowledged the work of Heritage New Zealand, Christchurch City Council, Opus Consulting, architect Sir Miles Warren and "the army of archaeologists, structural engineers, legal and planning advisors who helped identify all options".
"Once the deconstruction has been completed and a full investigation undertaken of the nave and the ground conditions, the diocese will be in a better position to consult more widely on the future of the Cathedral of the Blessed Sacrament," the church said today.
