This Just In

Building standards make difference in quake deaths

A facade lies collapsed while another building burns Saturday morning in Christchurch, New Zealand.

Cars buried in rubble, roads ripped apart and gutted buildings are some of the startling images coming out of Christchurch, New Zealand, after a magnitude 7.0 earthquake.

But the country's system of standards and quality control for building construction may have saved the affected areas from the death and devastation endured by the people of Haiti after a 7.0 earthquake in January.

"It comes back to building standards and the quality of construction, the materials used and the quality control in the building process," said Andrew Charleson, an associate professor at the Victoria University of Wellington's School of Architecture.

The construction of every commercial and residential building in New Zealand has to be approved by the local city council in accordance with the national building code. Haiti's reputation for lax building regulation and weak code enforcement, on the other hand, left its citizens vulnerable to disaster, said Charleson, who is also director of the Earthquake Hazard Center, a nonprofit that focuses on earthquake-resistant construction in developing countries.

"In most cities in developing countries, people just build how they want to, and they build cheap and nasty and dangerous, and there's no building controls to force them to build to a higher standard," he said. "Buildings kill people because they haven't been built to high enough standards, and it's only an earthquake that exposes this reality."

Officials declared a state of emergency Saturday after the powerful predawn earthquake struck near Christchurch. Power was out in the northwest part of the city, while water and sewage services have been affected in several regions, the Christchurch Civil Defense Group said. Roughly 100 people were being treated for minor bumps and cuts and two people suffered more serious injuries.

New Zealand has seen its fair share of earthquakes - about 100 to 150 each year that are big enough to be felt, according to New Zealand's Insitute of Geological and Nuclear Sciences. It's the price of living on several active fault lines, including the Alpine Fault, which runs for about 600 kilometers up the spine of the South Island and forms the "on-land" boundary of the Pacific and Australian Plates.

It took what most New Zealand residents refer to as "the last major earthquake" to set the country on its path toward current regulatory standards, Charleson said. The magnitude 7.8 Napier Earthquake of 1931 devastated the cities of Napier and Hastings, leaving at least 256 people dead and setting the art deco architectural design standard that remains in place today.

"That was the earthquake that started New Zealand down the track of better building standards. So this quake is going to be up there in terms of its influence on the resilience of New Zealand cities," Charleson said.

Of course, it helps that New Zealand has a first-world economy with a gross domestic product of US$115.3 billion, compared with Haiti, the poorest country in the western hemisphere with a GDP of US$11.99 billion. About 80 percent of Haitians live under the poverty line, according to 2009 estimates from the CIA's World Fact Book.

As a result of its seismic activity, the country has some of the world's top experts in earthquake engineering, many of whom come out of the University of Canterbury's engineering department. And, like most countries that experience frequent seismic activity, New Zealand has incorporated earthquake design principles into its building code.

"We've got a really robust building control system which very strongly recognizes seismic risks and takes those into account," said Graeme McIndoe, a Wellington-based architect and urban designer who recently served as a consultant to the New Zealand government on its Urban Technical Advisory Group.

The key is to construct buildings out of material that's "ductile," or the opposite of brittle, so they won't suddenly crack and collapse during an earthquake, McIndoe said.

To achieve this goal, most residential housing tends to be made of light timber frames that are inherently ductile and stand up to force, he said. Commercial buildings consist mainly of concrete reinforced with steel to deal with the tension.

In fact, New Zealand's strict building code has been criticized for being prohibitively expensive, McIndoe said.

"At the moment, the concerns are largely to do with housing affordability, that our controls are too rigorous and the processes too time-consuming, which add to the cost and complication," he said. "The requirements are not an issue. We know if we get the construction right, we have a chance at getting through an event without loss of life and minimal damage."

But it wasn't always that way. The images from Christchurch of toppled brick buildings and reports of at least one serious injury caused by a brick chimney that fell on a man evoke an era of less stringent building codes.

"Brick buildings are sturdy against small levels of earthquake, but once the earthquake gets to certain intensity and the bricks start to break, there's no steel reinforcement in the system to stop the building from being incredibly brittle," Charleson said. "It's that lack of reinforcement that's the problem. Unreinforced brick is incredibly hazardous."

Then there are the damaged roads and ruptured water and sewage pipes. The roads in Christchurch rest atop loose sand and peat that turns to mush during an earthquake, ejecting sand upward and disturbing pipes, Charleson said.

Such damage comes with the seismic territory, he said.

"We do have certain standards for roads, but the thing is roads have to go everywhere. We could design a road that wouldn't damage but would be prohibitively expensive, and it's relatively easy to repair roads. A society just couldn't afford to make roads damage free."