Saturday, October 15, 2005
Codes for Hurricane-Resistant Buildings
This is an article copied from "The Wall Street Journal" on October 5, 2005 with added emphasis:A preliminary study of wind damage caused by Hurricane Katrina says 79% of it [wind damage] could have been prevented if houses had been fitted to modern building codes, like those adopted in South Florida following Hurrican Andrew in 1992.
Louisiana is only a handful of states that has no statewide building code, and many cities and towns don't have codes. The study used wind maps from Katrina, census data and past storm effects in a FEMA-created program caled HAZUS-MH to model how wind and wind-driven rain affected houses in the state.
The program pegged the actual physical wind and driven-rain damage at about $10 billion. (The study didn't include the issue of flooding, which caused most of the damage in New Orleans.) By using impact-resistant windows and stronger doors, 45% of the damage would have been prevented, while improved roofing techniques such as so-called hurricane clips and better nailing of shingles would have prevented 31%.
Marc L. Levitan, director of the Louisiana State University Hurricane Center, performed the study and spoke yesterday before a panel considering building codes for Louisiana. "Why in the world aren't we going to do this if we're going to hugely reduce the damage we face in the future?" he said.
Doesn't sound good, does it?
In a 2001 article, Levitan outlines the building features that can prevent this damage, such as hurricane shutters, in-house shelters, hurricane clips, hurricane storm windows, impact resistant glass in windows, double pane windows, hurricane-resistant plywood and storm shutters. He also states that many homes have been built in South Louisiana with hurricanes in South Louisiana, although there are no code requirements for them. These clips can prevent damage from about 75 to 100 miles per hour. They are not typically built like that in North Louisiana, which is where it seems that most of the damage could have been prevented. A wind speed map of Katrina shows that most of the areas hit by the storm were hit by winds that were near or under this speed.
Another article, Hurricane 2002: New State Building Code Lacking, Experts Say, talks about building codes in the non-coastal regions of the panhandle of Florida, which as of 2002, did not adapt those hurricane codes. This article states that homes in Collier must be built to withstand 140 mph winds. Referring to the wind speed map again shows that nearly all the affected areas were hit by winds less than this speed.
Overall, Levitan recommends "a national model code and linking code requirements to the more commonly known hurricane categories to help the public understand the often arcane language of building codes." These codes should also take into account termite intrusion, which is prevelant in both the Gulf region and in Florida. These codes would probably still allow stick building, but it would be great if they required concrete construction in the potentially heaviest-hit areas. Another advantage of some concrete homes is that they are flood-resistant as well. (Note: I have a magazine article that seems to have wandered away about a residential home builder in Florida which builds these homes and has had them tested in the Florida hurricanes last year. Once I find it, I will update this post. Thank you for your patience.)
I guess it's alot to ask just for the codes like Collier's. Here is contact information if you would like to write the Louisiana government officials.
Other links for Louisiana building codes:
Levitan's June 2005 Testimony to the US Senate Committee on Commerce, Science and Transportation. In it, he mostly promotes a national code for wind storm shelters, but also discusses other deficiencies of buildings in the face of strong winds.
Sustainable Redevelopment. Although this is mostly a great idea, it's not going to help if the houses keep falling down every few years.
President Bush's Post-Katrina Speech. He makes a reference to the existing deficient building codes.