The demolition of the northeastern area of Queensgate Mall in Lower Hutt is under way.
Structural engineers declared the building unsafe and advised that it be demolished as soon as possible, in the wake of the recent 7.8-magntiude quake.
The area to be demolished is structurally a separate building to the rest of the mall and includes a section of car park and Event Cinemas Queensgate.
A crane with powerful jaws has begun tearing the side of the building, causing debris to fall into a prepared safety zone.
A small crowd has gathered to watch the demolition, with many people saying it was a shame, but probably necessary.
Work at the site was due to start at 7.30am, but engineers needed to check the building again following yesterday's magnitude 5.5 aftershock near Seddon.
Sensors will monitor the movement of the buildings and engineers will assess to see if there is any damage.
It's expected to take two months to fully demolish the building, he said.
Meanwhile, the Ministry of Justice said the Wellington High Court building was now not likely to re-open until early next year.
The building was closed after the 14 November earthquake.
The Ministry said it had been cleared by engineers as being structurally sound.
However, the interior experienced significant water and other damage.
In the meantime, the High Court registry will continue to be provided at offices of the Wellington District Court and hearings will be held at various courts around Wellington.