Are America’s Building Codes as Good as Japan’s?

Real estate, Money

Japan’s rigorous building codes saved lives in the wake of the devastating earthquake and resulting tsunami that hit the country earlier this month.  The March 11 earthquake, which measured 9.0 on the Richter Scale, was the fifth-strongest on record. With 10,000 people dead or missing and potentially billions of dollars in damages, it’s hard to imagine it could have been much worse.

However, the damage would certainly have been more extensive if not for buildings specifically designed to resist earthquake damage. For comparison, the 7.9 magnitude quake that rocked Sichuan, China in 2008 affected primarily rural areas where building codes were loosely, if at all, enforced; the official death toll there was nearly 70,000 with over 300,000 injured, many trapped in collapsed homes and schools.

If – some say when – a comparable earthquake hits the U.S., will we be as prepared as Japan?

The Ring of Fire

About 20 percent of all earthquakes with a magnitude 6.0 or greater occur in Japan, due to the nation’s location on “Ring of Fire,” a line of frequent seismic and volcanic activity that circles the Pacific Rim. As a nation familiar with earthquake damage, Japan began enacting regulations designed to strengthen buildings as early as the 1920s, after the 1923 Kanto earthquake caused widespread devastation.

Every seismic event since has led to further refinements in making structures as earthquake-proof as possible. Most recently, after the 1995 Kobe earthquake that killed 6,000 people, Japan invested billions of dollars in structural engineering research. Rather than rely solely on solid construction to resist the effects of an earthquake, new construction is geared toward vibration control techniques and base isolation technologies, both of which allow a building to absorb ground shake and move with the earth. Nothing can guarantee a building’s survival during a quake, but the focus of building codes in Japan minimizes the damage as much as possible in order to save the lives of the occupants.

San Andreas and New Madrid

Earthquakes are also a very real threat to 75 million Americans in 39 states, according to the U.S. Geological Survey. Areas along the San Andreas Fault on the California coastline face the greatest threat; seismologists believe that fault is long overdue for a major quake. But Californians aren’t the only Americans at risk. Two other areas are earthquake risk zones as well. The first is South Carolina, which was the site of a catastrophic earthquake in 1886 that destroyed a quarter of Charleston’s buildings and killed over 100 people.

The other, the New Madrid fault, extends 150 miles along the Mississippi River from Illinois to Arkansas. In 1811 and 1812 the strongest earthquakes to ever hit the U.S. occurred here, with magnitudes estimated up to 8.0. New Madrid is also thought to be overdue for a major event; seismologists estimate a 90 percent chance of a quake between 6.0 and 7.5 magnitude in the area before 2040.

Building Codes: The Good, the Bad, and the Ugly

The recent earthquakes in China, Haiti, Chile, and now Japan have focused attention on building safety in earthquake-prone areas. While Japan has spent billions of dollars retrofitting older buildings, codes in the U.S. have not always kept up with engineering developments. The International Code Council (ICC) developed the set of codes most widely used in the U.S., but the seismic regulations have been only minimally updated since 2000. In addition, enforcement of building codes vary by state and local jurisdictions:

The Pacific West Coast: California, Oregon, and Washington

Of the three U.S. regions most prone to earthquake activity, the West Coast has the most stringent building codes. All three states have mandatory statewide codes in accordance with the 2006 ICC codes; each also added seismic protection requirements that exceed the minimum regulations.

South Carolina

South Carolina adopted mandatory statewide codes in 2003 and follows the 2006 ICC regulations, without amendments to the seismic protection requirements. The state meets what FEMA considers “acceptable levels” of earthquake safety, but many older buildings have not been updated or retrofitted with earthquake-resistant engineering.

The Central U.S.

The New Madrid seismic zone is far less prepared, even though it stretches through seven states and covers an area 20 times larger than San Andreas’ danger zone. Arkansas, Illinois, and Missouri have no mandatory building codes, although individual jurisdictions such as the cities of St. Louis and Chicago have adopted city-wide requirements. Tennessee, Indiana, and Mississippi have statewide codes, but some jurisdictions and areas are exempt, or rely on understaffed local inspection departments to enforce the codes. FEMA reported in 2008 that a serious earthquake in the New Madrid zone could result in “widespread and catastrophic” damage: tens of thousands of fatalities and billions of dollars in property damage would be seen throughout the region.

The Bottom Line

California has building codes similar to Japan, but Japan has invested far more than the U.S. in retrofitting older buildings with the newest technologies available. If the next big earthquake hits the Pacific West Coast, there will be property damage and loss of life — perhaps comparable to what we saw in Japan, perhaps less. But if the Big One hits the central U.S. and nothing has been done to enforce stricter building codes in the region, the extent of the tragedy will be far worse.