A total of 185 people died when the quake struck in February last year, 60 per cent of them in the CTV building.
The report says the Christchurch City Council should not have issued a building permit in 1986 because of numerous design deficiencies.
The report says there were shortcomings in the engineering, design and construction of the building.
The commission did not find a link between the building's collapse and any failure in building inspections after an earthquake in September 2010.
However, the report recommended improvements in the inspection process as well as changes in building practices and oversight.
It found the building was cleared for re-occupancy after the September 2010 quake even though there was no engineer present for the inspection.
New Zealand prime minister John Key says the report makes for "grim and sobering reading".
Mr Key says the government will consider the commission's recommendations for changes to the building approval process and evaluation practices.
David Beaumont, whose 31-year-old son Matthew died in the CTV building, says he hopes the royal commission will help prevent similar tragedies in the future.
"If we tighten up legislation as much as possible, if in future there is a disaster, we can keep things to a minimum with people," he said.
Mr Key says the government will issue its response to the royal commission next year.