"Across the 16 buildings, there are 50 different tenants," it said, citing IRD with just under 28,000sq m of office space losing the most area.
Some buildings will be out of stock for a few weeks while others will be removed for more than six months.
A list of top tenants affected show major Government entities and big corporates, including Vodafone.
In the past three weeks, there has been a big flurry of activity as large occupiers try to find accommodation while their buildings are shut. BNZ has been the most active, finding new space in six different buildings throughout the city.
"All six locations are within the CBD, representing 11,500sq m which is around 56 per cent of the pre-quake space requirement," the report said.
But some large government occupiers such as IRD and the Ministry for the Environment have not committed to any new space.
"It is currently believed that the Asteron Centre where the majority of IRD is housed will be re-opened just before the end of the year so no substantial leasing will be required but that does not address the space which has been lost in the Deloitte Building," the report said.
Vacancy rates in Wellington will reduce due to the reduction of building stock.
"Investment within the city has slowed which is a predictable response to any natural disaster. Investors are reassessing the market and are unlikely to make any new deals before the end of the year as December is a traditionally slow period," the report concluded.
But the investment freeze is expected to be short lived. More relocations of Wellington CBD office tenants this month are predicted as tenants learn more about how their buildings performed in the earthquake, how shut buildings will remain closed and how extensive future strengthening programmes will be, the CBRE report said.