Gas and electricity supplies to a 10-storey central Wellington building are being turned off so it can be demolished safely.
Damage to the high rise at 61 Molesworth Street has left it at risk of collapse in a strong aftershock, and forced the evacuation of surrounding buildings and homes.
Specialist company Ceres, which demolished many quake-damaged high-rise blocks buildings in Christchurch, will be carrying out the work, which Wellington City Council expected to take about two weeks.
An 85 tonne ultra-high-reach excavator has arrived in the capital from Christchurch and will be moved on to the site in the next couple of days.
It will be used to to deconstruct the building, starting from the top.
Council building control manager Mike Scott said the start of work largely depends on how long it would take to turn off electricity, gas and other services to the building.
"There's a lot of electrical gear in the building that actually isn't part of the building, but more of a substation for the network authorities."
It was complex to turn off services quickly and safely because no-one could enter the building and everything had to be done remotely.
The council was meeting network representatives this morning to carry out "detailed planning".
The cordon area around 61 Molesworth Street was reduced over the weekend, which means the Cathedral of St Paul and Loaves and Fishes Hall are accessible.
Mr Scott said Molesworth Street should be at least partially open and people allowed back to some of the nearby buildings within the next 10 days.
Cruise ship docks at Wellington port
This morning, the first cruise liner docked at Wellington since last week's 7.8 quake.
Australian passengers on the P&O ship Pacific Aria said they were not worried about the earthquakes.
"I feel quite safe," said Barney Marsh from the Gold Coast.
"You guys live with this all the time, and we trust the Kiwis."
Damage to the port is more extensive than during the 2013 Seddon earthquakes, the port company said.
Parts of the facility are operating including the ferries and a rail link, commercial vessels are unloading cargo and navy ships had been at the port.
But the container shipping operation, which been shut since the quake, remains suspended.
Managers do not know when it will be able to reopen, and import and export business is being diverted to other ports.
Many buildings remain off limits, with staff working in back-up locations across the port and outside the CBD.
Elsewhere in the capital, NZ Post House, opposite the railway station, is structurally sound but most staff still have to work from home while the interior is cleaned up.
Work is proceeding on a full re-opening of Lower Hutt's Queensgate shopping centre, the biggest mall in the southern North Island. So far only a handful of shops are back in business.
About 150 people evacuated in Wellington from apartment buildings around the quake-damaged Reading car parking building will have to wait at least a month before they can go home.
Forty others evacuated from a building in nearby Tennyson Street are also unable to return home until repair work is completed.
Mr Lavery said most evacuees had already made arrangements to stay with friends or family.