Floating house could ride New Orleans’ floods

Someone garbled the reason that the Netherlands has been working on this.

The problem those houses are meant for is not rising sea level - if the dikes get seriously breached the rushing flood water would pose problems that no floating houses could solve. The issue is that global warming is expected to bring increased storms, and therefore larger floods coming into the Netherlands down the Rhine. There is a limit to how quickly that flood water can be pumped out, so sections of the Netherlands have been targeted as temporary floodplains in case of emergency. However all of the Netherlands is fairly densely populated, so there are a lot of people living in those areas.

Therefore effort is being put into designing floating houses, roads, etc for these areas so that people could get by with minimal damage even if they are several meters deep in water.

So here's what I don't understand... Why build a house on the ground in a floodplain in the first place?

If it's going to float up a pylon to 12 feet when the water rises why not just put it a story off the ground on stilts to begin with? Seems like it would reduce some of the unnecessary complexity this house has and maybe even reduce the needed footprint since you could do things like park vehicles under the house when a catastrophe is not in progress...

Anyway logical reasons why this was not considered?

Another wrinkle in the "fab-prefab" movement. Why is it that beautiful, well designed manufactured homes aren't already the norm? What are the barriers?

"While not intended for occupants to remain inside during a hurricane, the structure is designed to minimize catastrophic damage and preserve the homeowner’s investment, Mayne says.

In case of a flood, the base of the house acts as a raft, allowing the home to rise on guide posts up to 12 feet as water levels rise. In the Lower 9th Ward, which saw some of the worst flooding in the city during Katrina, floodwater reached as high as 12 feet."

Looks like this helps 'preserve' your house in the event of flooding.