The term Modular Home raises the image of the double-wide mobile home, shipped as two units, and bolted together to make a single structure. And when you think of mobile home and safety, the slang term "tornado bait" comes to mind. There are more to modular homes, however, then the double-wide you see being trucked down the highway, and their ability to stand up to the elements can often be better than a home built on site.

While the terms mobile homes and modular homes are often used interchangeably, the housing industry has been trying to draw a distinction between the two. Adding to the confusion is the U.S. Department of Housing and Urban Development, which officially identifies mobile homes as "manufactured homes," though in fact both mobile homes and modular homes are manufactured at a central facility. But the term modular home as used by the housing industry is a structure permanently assembled at a home site, and is often indistinguishable from a site-built home.

When Hurricane Andrew hit Florida in 1992, the damage from the force 5 hurricane was widespread, but mobile homes were especially vulnerable. As a result, HUD came up with with new standards for the homes linked to designated "wind zones." A mobile home built and secured to wind zone one standards could not be placed in wind zones two and three. In Florida, the state's Department of Highway and Motor Vehicles noted that 53 of the state's counties are designated as being in wind zone two, and the remaining 14 counties along coast areas are in wind zone 3, "requiring the most stringing construction standards."

The key difference between the two is what's underneath. Mobile homes, including double-wides, are built on a chassis with wheels, though the chassis may be hidden by a metal skirt. They are built to be temporarily located at a site. Check the air in the tires, and the owner can move the owner to wherever she wants, or trade it in for a new model. Which wouldn't be a bad idea, because older mobile homes can be susceptible to damage from high winds. News reports on major storms often shows mobile homes and even double-wides knocked over on their sides.

Modular homes are built on the same type of foundations as site built homes, and can better withstand storm damage.

In many ways, modular homes are studier than site-built homes. Both are built to local and state building codes. But modular homes have to be built strong enough to move from the factory to the home site, so framing is often stronger than called for by the codes, making modular homes even more likely to withstand damage from high winds.

Mobile homes fall under federal HUD regulations rather than local building codes. Although local zoning ordinances could restrict and even ban the placement of mobile homes in certain locations, local governments could not require stiffer building standards because the homes were never permanently attached to the land, legally or physically. And since these homes were meant to be temporary housing, federal standards were not as strict as local building codes. It took a mighty strong wind to improve those standards.

A report posted on HUD User, the information service for Kit Home, noted that since then, "the evolution of the industry itself, and the diversification of the potential customers for manufactured homes are ushering in a host of innovations and changes to the industry's core products. No area is more affected by these changes than the methods for supporting and fastening the home to the ground."