The Government has declared that more than 1100 homes in the Port Hills area of Christchurch are now safe for their owners to live in.

The decision to rezone 1107 properties from white to green ends a wait dating to the February 22, 2011 disaster.

Homeowners can start moving back in this afternoon and start talks with private insurers and the Earthquake Commission about repairs.

A further 166 people remain in limbo, with their houses needing further assessment, and 285 homes remain red-zoned because they're too dangerous.


See the new zone map here

Canterbury Earthquake Recovery Minister Gerry Brownlee said he was aware it had taken "a long time'' to complete the work so far but said Christchurch was in a "unique situation''.

He promised a final decision on the remaining white-zoned properties by August 17.

Many of the 1558 Port Hills properties still white-zoned before today, in areas like Sumner, Redcliffs, Clifton and Lyttelton, have been affected by cliff collapse, landslides and rockfall.

Scientists said today the risk to homeowners had eased and would continue to do so as the earthquake sequence tails off.

The red-zoned homes are too dangerous to live in, or too expensive or difficult to make safe because of the risk of cliff collapse, landslips and rock roll.

Scientists say rocks weighing upto 10 tonnes could reach speeds of 90km/h when bouncing down the hills.

The risk of deaths in red zone areas was between one in 100 and one in 1000. The Government said the accepted level of risk is about one in 10,000 - about the chance of dying in a motorway smash.

Many of the red zone decisions were ``ultimately clear cut'', Mr Brownlee said.

Owners will now receive the Government's offer to buy their homes.

Mr Brownlee said the total cost will be shared by the Government and the city council and is expected to be around $205 million.

The minister accepted the red zone announcement would be a ``shock'' to some residents, especially those who have been living in homes that have not been subject to Section 124 notices prohibiting occupation of houses on safety grounds.

He said it had been one of his most difficult decisions since the devastating string of quakes began in September 2010.

"We're acting on information which has only recently been finalised through state of the art geotechnical analysis,'' Brownlee said.

Cera chief executive Roger Sutton said a lot of work had been done to blast rocks away from important areas like roadsides, but often that created more problems and more rock falls.

"It frustrates me a lot that we're not there yet,'' he said.

Mayor Bob Parker said he was pleased so many people got clarity over their futures today, but said his thoughts were with the red zoners and remaining white zoners facing weeks more uncertainty.

Mr Brownlee's announcement was interrupted by a strong magnitude-4 jolt, which he said was a timely reminder that Christchurch is still very much an active seismic zone.

Port Hills MP Ruth Dyson said today's news would be met with mixed emotions by people who had suffered a "long and painful'' wait.