Christchurch Earthquake 2011
Fixing Christchurch's earthquake-hit high-rise buildings will take five years, and some could be demolished to save time, the Earthquake Engineering Society says.
Society chief executive Win Clark said it would take about five years to repair many damaged multi-storey buildings in the central city.
This may be too long for civil authorities and adjoining businesses, and some salvageable buildings would be demolished to allow parts of the city to be reopened faster, he said.
"Demolition will be the most economical solution in some cases."
Clark said some owners were already under pressure to demolish their buildings to allow adjoining premises to reopen.
"The problem will be if people go to litigation," he said. "Then you can forget about five years; we are talking about 10 years."
Civil Defence last week released a list of more than 120 buildings earmarked for demolition, including high-rises such as the Hotel Grand Chancellor in Cashel St and BDO House in Victoria St.
Other damaged multi-storey buildings, such as the Clarendon Tower, are preventing parts of the city from reopening until they are stabilised or repaired.
Civil Defence said there was no pressure on owners to demolish or speed up repairs.
Civil Defence controller Steve Brazier said yesterday that decisions to demolish or repair high-rise buildings had been obvious, with no disagreements between Civil Defence and owners.
However, civil authorities would have to make some "difficult calls" in coming months, he said.
They would be a matter for the new Canterbury Earthquake Recovery Authority, which would take over from Civil Defence when the state of emergency was lifted, he said.
Brazier said any buildings that took five years to repair would almost certainly be cheaper to demolish. "It's just not economical to have a building empty for five years."
The 17-storey Clarendon Tower has suffered significant damage and contractors say it will take about three months to prop up the building floor by floor for safe access. Civil Defence has identified it as having a "drop zone" that would encompass several surrounding buildings if it collapsed.
Property manager Mark Youthed, of Knight Frank, said everyone was working as quickly as possible to stabilise the building, but the extent of the damage was still unclear.
On first inspection the Clarendon Tower had been deemed reparable, but it would be up to insurers and the owner to decide whether to repair or demolish, he said.
If the building was fixed, he expected it would take at least a year.
Plans are being made for the slumped 27-storey Hotel Grand Chancellor to be partly or totally taken down.
Hotel general manager Steve Martin said yesterday that a tender to bring down the building would close on Monday, with possible methods including controlled implosion or using a crane and wrecking ball.
He did not expect demolition to take more than four months.
There was no pressure from other business owners or Civil Defence to move faster, he said. "We don't want to be seen to be holding up the reopening of the central city."
Crystal Imports Ltd director Gordon Chamberlain owns five properties in the central city, two of which he expects will be demolished.
He was frustrated about being unable to get within the cordon to assess his properties, and he believed the recovery was mired in a growing web of bureaucracy.
One of his buildings, the old post office in Cathedral Square, had only minor damage but would probably have to wait years for the demolition of or repairs to nearby high-rise buildings.
"These buildings are blocking off large parts of Christchurch."
He expected it would be at least two years before he was able to begin repairs on his properties.
Chamberlain said that if any of his buildings were demolished, he was unlikely to rebuild. Instead, he would use the insurance money to build out of the city centre.
"Christchurch is going to be a ghost town for a long time," he said.
- © Fairfax NZ News
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