According to FEMA, all houses rebuilt or built in the future must follow guidelines if they are to qualify for flood insurance. This area would not have flooded had the U. S. Corps of Engineers been competent enough to build and maintain decent Canal levees and floodwalls. This is about 4 blocks from the break in the 17th Street Canal levee. There was a house built on a slab here that was heavily destroyed. The owners demolished it and are now building some 10 feet off the ground.
To build this way or lift your house to this height is very expensive and many people chose not to live here anymore. To raise a house 10 feet costs in the range of $70,000-$100,000 just for the lift.
It also makes no sense to raise a house 8 to 10 feet if the area flooded to 20 feet.
New Orleans' houses and buildings, beginning in the 1700's were mostly raised above the ground for the times when the Mississippi River would overflow. In fact, most houses along the Great River Road were raised. In the 1950's a new building craze took over and slab houses became "the thing." People thought they were safe from flooding because of the levees.
Go figure. Government is really taking over.