VOL. 121 | NO. 217 | Tuesday, November 7, 2006
Real Estate & Development
Earthquake Code Enforcement Better Late Than Never - But it Will Cost You
By Zachary Zoeller
CORNERED: The enforcement of seismic building codes in Shelby County focuses on strengthening corners of houses, like this one on a new house in Collierville. Only houses built after Nov. 1 will be affected. -- Photo By Zachary Zoeller
From now on, homes built in Memphis, Bartlett and Collierville will be ready to shake and rattle but not roll.
Last week, Shelby County building codes inspectors began enforcing rules designed to make new single-family homes more stable during an earthquake or high winds.
As for the design and construction of walls and foundations, the codes actually have been on the books for years, but no one had gotten around to interpreting and enforcing them until last year, said Lynn Hicks, director of code enforcement in Collierville.
"I think Shelby County as a whole has been so busy in the past that it was a matter of continuing to do it the way it has been done in the past," Hicks said.
Collierville town administrators charged Hicks with evaluating the city's emergency preparedness plans after hurricanes Rita and Katrina hit the Gulf Coast last year.
"It occurred to me that the requirements for seismic concerns have not really changed over the last 15 years as far as what's being done out in the field," he said. "I found out we were lacking somewhat in wall-bracing requirements."
After a months-long education effort, local code enforcement officials worked with homebuilders to come up with a uniform code in Memphis, Bartlett and Collierville.
"We did not fight with code enforcement on this, but we finally nailed it down to what issues we're going to address and how we're going to address them," said Tim Wilson, board president of the Memphis Area Home Builders Association.
The codes focus on the corners of homes, which are crucial to their stability, Wilson said.
A prefabricated panel is installed on the front and back sides of stud walls to reinforce the corners. However, corners that are at least four feet from windows or doors do not require the panels.
In the corner
The panels can cost from $500 to $1,500 each, inevitably driving up the cost of homes, Wilson said. As most houses average eight to 10 corners, he expects costs of homes with building permits pulled after Nov. 1 to rise as much as 3 percent.
"We definitely want to build safe homes for the customers, but we have to turn a profit or we go out of business," he said.
The average price of a new home in Collierville's 38017 ZIP code during the third quarter of 2006 was $413,639, according to real estate information company Chandler Reports, www.chandlerreports.com.
If enforcement of the codes results in a 3 percent increase, the average price would rise to $426,048.
Wilson says the additional cost is just another in a year full of them.
"Every product that goes into a home has increased price-wise," he said. "There is a market out there, and we can only sell the houses for what the market will take."
Steve Hodgkins of Oaktree Homes LLC agrees with the estimate of a 3 percent increase.
"The more complicated the house, the more offset it has - those types of things will make it more expensive," Hodgkins said. "It's definitely going to make the houses stronger, which is probably going to save some lives."
However, the possible loss of some customers because of higher prices concerns him.
"Any time you raise prices, you eliminate a certain number of people from the market," he said.
It's our fault
While Shelby County is far out of reach of hurricanes in the Gulf of Mexico, it sits along the New Madrid fault, which caused three earthquakes from 1811 to 1812. The quakes, which ranged from what is now equivalent to 7.2 to 8 on the Richter scale, caused damage as far away as Washington, according to the Central United States Earthquake Consortium (CUSEC).
A New Madrid earthquake with a magnitude of 7.5 is 90 percent likely within the next 50 years, according to the United States Geological Survey's Earthquake Probability Mapping system.
"It's going to happen, but when, we're not for sure," said Shahram Pezeshk, professor of civil engineering at The University of Memphis.
Earthquakes of moderate magnitude can be very damaging as well, evidenced by the magnitude 6.7 quake in Northridge, Calif., that caused 33 deaths and $20 billion in damage in 1994, according to CUSEC.
Out of sight ...
Pezeshk draws a comparison between the 150-mile New Madrid fault line, which runs from the top of the Missouri Bootheel to central Arkansas, and the 800-mile San Andreas Fault that nearly runs down the entire California coastline.
"The difference between us and California is that in California it happens often, but with us it doesn't happen often and people aren't thinking about it," Pezeshk said. "That makes it dangerous because when you don't think about it, you don't prepare yourself as much."
Because of the geological structure around the New Madrid fault, the shocks would be felt across a much broader area than an earthquake of similar magnitude in California, he said. Some differences in geological structure would be California's location on a coastline and the unconsolidated sediment in the Mississippi Valley.
Coupled with growing population densities in St. Louis and Memphis, another New Madrid earthquake could be very damaging.
"Based on the historical knowledge that we have, if something like that happens, it could be something like Katrina, and we'll be in real bad shape," he said.