Work to bring the Hotel Grand Chancellor in Christchurch to the ground begins on Monday, when contractors start removing the roof of the 28-storey building.
The hotel was badly hit in February's earthquake.
The Canterbury Earthquake Recovery Authority (CERA) says it believes this is the most challenging demolition project in the world.
A structural engineer with the Recovery Authority Carl Devereux, says once the roof is removed, about 16 November, it should take about seven days to demolish each floor.
By March 2012, Mr Devereux says, the top 12 floors will be gone, allowing access for the first time since the earthquake to several buildings in close proximity to the hotel.
He says the bottom part of the building will be fairly straightforward to take down, and the demolition should be completed by April.
CERA says the cost of tearing down the Grand Chancellor will be about $10 million.
Wall collapse affected whole of building
A Department of Building and Housing report, released in late September, investigated why three central buildings, including the hotel, collapsed on 22 February.
A wall in the building expected to carry substantial earthquake loads collapsed, the report said.
The failure of the wall, which supported one eighth of the building's mass, significantly increased the damage to the building.
The report says the concrete wall's collapse caused the failure of a major stairwell and columns and beams.