Reinforcing buildings worthwhile

01/12/2010

by Liz McDonald, Christchurch Press

Earthquake strengthening has proven its worth and commercial landlords should be thankful for it, a Christchurch engineer has told a group of investors.

Holmes Consulting director and engineer John Hare told investors at the Property Council's annual conference that a major revision of earthquake building codes after the September 4 quake was unlikely.

He said while the codes might have been deemed a failure by landlords with damaged buildings, engineers considered them a success because no-one died.

'We've got codes designed to protect lives, not to protect the value of your investment,' he said.

'By and large buildings designed to cope did OK.'

Hare made news himself after the quake when, caught dangling from a crane above a damaged church when a big aftershock struck, he clung to the church's stone cross and escaped unscathed.

He told the conference that unreinforced masonry buildings came through the quake if they had been strengthened, but failed if they had been ignored. Brick had fared worse than stone.

Most well-constructed modern buildings held up well with the exception of some taller, flexible buildings, and concrete-and-steel buildings mostly withstood damage.

On the whole, damage to modern buildings had been to nonstructural elements.

Hare said there were surprises in the earthquake, such as how little damage was done to properties on Christchurch's Port Hills.

He also gave the landlords advice for the future. 'What should the wise investor do?' he asked.

Existing owners should continue to strengthen buildings against future quakes, Hare said. 'Strengthening seems costly, but is easier than losing your building.'

They should also expect higher insurance premiums. He advised those buying commercial property to 'get a great geotech [report].'

Not all old buildings were a bad earthquake risk and not all new ones were great, he said.

Hare told investors intending to build to demand their consultants design for damage limitation instead of failure.

'Consider reparability, and think about your tenants.'

Thanks to The Press for this article.