David Willens' South Florida concrete mansion, listed at $27.5 million, is built to last; the design incorporates commercial-grade impact glass, post-tensioned concrete floor slabs, and a dual fuel-generator, which help the home withstand 180 mph hurricane winds. After Hurrican Irma, the home sustained no damage. The post-tension concrete floors and poured concrete walls were selected for their durability. The concrete mix included additives to mitigate water and protect the home against corrosion.

"'There’s no exposed steel to rust, as in most Florida homes. Solid concrete is much stronger than the cinder block construction of most Florida homes,' says Willens."

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