Cantabrians worried about the safety of their homes are being urged to call a council building inspector or a certified builder.
Christchurch City Council says building evaluators are working
today to assess buildings.
Red placards will be placed on buildings deemed unsafe and which cannot be entered. Yellow placards will indicate restricted use, and green will show buildings that are safe.
Anyone with concerns about anything at all - buildings, homes, and their own welfare should call the main general number which is 0800 77 9997.
Many worried Cantabrians flocked to welfare centres overnight, where they were supported by Civil Defence and volunteers.
Shelters are operating at Linwood High School, Burnside High School and Addington Raceway and anyone without power or who was feeling unsafe was encouraged by Prime Minister John Key and local authorities to head to one of the sites.
Civil Defence and the Salvation Army have provided food, hot drinks, and sleeping areas.
ONE News reporter Lorelei Mason was at one of the centres overnight and said many of the people there did not have damaged houses, but were too terrified to return home.
She said some had suffered from panic attacks.
All the people ONE News spoke to said they felt safe and comfortable and were glad they had headed to the centres as they were still very scared about aftershocks.
Aftershocks have rocked the area overnight with one shortly before 6am that registered 5.1 on the Richter Scale. There have been around 50 aftershocks since yesterday's 7.1 earthquake.
Russell Lindebaum said he went to one of the centres after the house he was staying in started to lose its roof.
"It's really not safe to live there especially as with the bad weather coming in. We were originally going to go and camp at the Waimak (Waimakiriri River) but we decided, nah, that's not a very good idea."
Lindebaum says the people running the centres were very welcoming and everything seemed planned and well thought out.
"They gave us coffe, tea, some warm tucker, what more can you ask for?"
He said he wasn't concerned about the number of people or level of noise but still felt uncertain about sleeping inside a big building when another earthquake could hit.
Jennel Hopkinson, who is 26 weeks pregnant and was staying in the same house as Lindebaum, says she went to the shelter because she felt nervous.
They heard about the shelter on the radio and thought it would be better than their house.
"(We feel) a lot safer here than at home. The people have welcomed us in and given us everything we needed," Hopkinson said.
Samantha Tindall told ONE News she had to hold onto a door frame throughout the 7.1 magnitude quake and found it "very intense."
She was also planning to camp at the Waimakiriri but had heeded the advice of others to use one of the welfare centres instead.
"Everyone has taken good care of me, they have been really considerate," Tindall said.
Tindall, who has a heart condition, says she still feels nervous that another big quake could strike anytime but believes she is "much safer" at the Civil Defence shelter than her own home.
The Salvation Army staff and volunteers are organising the catering for the welfare centres.
Major Rex Cross, the emergency services coordinator for the South Island, told ONE News they were called out early in the morning and immediately started organising the centres.
Cross says they were told to expect 200 at each of the three centres but Burnside does have the capacity for 1500. He says the bad weather that is expected could mean more people will need their services.
Another person at the shelter, Vineshni Sharma, is there with her four-year-old son.
She said she felt very scared at home and after seeing the centres on the television news she had headed to Burnside High.
Sharma said her and her son were warm and comfortable and as she had no family in Christchurch, she was very glad she could come to a shelter.
Anyone who needs information on income support, housing options, health issues, community assistance, Civil Defence or any other government service can call the Earthquake Government Helpline: 0800 77 999 7.
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