About 200 of those who lost loved ones in collapsed buildings in the 2011 Christchurch earthquake, have heard an apology from the city's mayor Lianne Dalziel.

Yesterday marked nine years since the 6.2 magnitude earthquake which killed 185.

A royal commission into faulty buildings found serious errors by engineers and the Christchurch City Council.

David Selway who lost his sister, Susan Selway in the CTV Building, said it was good to hear a heartfelt apology from the mayor for the role her council played in signing off the building as safe.

"There were buildings in Christchurch where it was known that they had deficiencies and in the CTV building that was absolutely the case. It wouldn't have taken much effort for some flags to be raised from people who knew that there were deficiencies to prevent those deaths. And that's the really sad part."

David Selway said he would also like to hear an apology from the designers of the building.

Julie Hibbs lost her mother, who had been in the CTV building, seeing a doctor.

The 185 empty chairs memorial - decked with flowers from yesterday's anniversary. Photo / RNZ

She questioned why Dalziel was apologising now after nine years.

Ms Hibbs said she didn't think the apology would mean much to many people, and she would prefer that someone was in jail over the building's failures.

In a letter to friends and family of those who died, inviting them to today's apology, Dalziel said an apology was something she had wanted to do for a long time.

She said the end of the police inquiry into building failures means she was finally able to do this.

- by RNZ