Some business owners in the Christchurch CBD will have limited access to their premises from 8am.

There will be controlled access in orange zone four and some parts of the red zone.

Civil Defence National Controller John Hamilton says owners who can go and get essential materials have been contacted.

People with businesses in the first allocated grids who have registered on the website for access have already been

If business owners have not been contacted, it means their business is not in the first allocated grid.

"We are doing all we can to identify other grids for authorised controlled access as soon as possible, however some businesses will unfortunately not be able to access their buildings for the foreseeable future," said Hamilton.

- Newstalk ZB

This story has been changed from an earlier version that incorrectly said that if business owners who had not been contacted, it meant their building was too damaged.