But as Ms. Blumenfeld said: “The reason we’re going to rebuild is not because we can afford to. It’s because we can’t afford not to. Our house lost more than $300,000 in value in one night.”

There is nothing leafy about this wisp of a barrier island along the southern shore of Long Island. Its allure derives from the combination of the same delicate white sand and sparkling surf found in the Hamptons, with far more modest housing stock and a 50-minute rail commute to Manhattan.

The land mass is so small that children of a certain age can bicycle almost anywhere; they don’t have to be driven. When the surf is up, you see them heading to the beach, surfboards tucked under their arms. Of course, this cherished geography was a problem the night of the storm, when ocean and bay surged, meeting in some places. Ever since, the island has been filled with cranes, Dumpsters and storage pods the size of large rooms, along with the constant thrum of construction and truck traffic. And worry.

Over on East Hudson Street on a recent afternoon, Robin Antila, 59, was unloading a few things from the storage container in front of her house. She invited a stranger in to see the renovation of the first floor, but seemed prouder of the makeshift kitchen tower she had put together in the master bathroom upstairs: a mini-fridge with a microwave and a toaster oven stacked on top. Even with her gleaming new Craftsman kitchen up and running, she can’t bring herself to dismantle the temporary one that sustained her family for months.

Of the 9,500 homes in Long Beach proper, city officials say very few escaped some level of harm. After FEMA inspections, 865 were declared “substantially damaged.” In other words, the cost of repairing any of these homes would be more than half their appraised value. In a letter from Scott Kemins, the city building commissioner, these owners were given two options: raise the houses to an elevation determined by FEMA flood maps or remove them from the flood plain altogether.

Those with less-damaged property were, for the most part, left to decide for themselves how to spend whatever insurance money they received. But altogether, 20 to 30 percent of the 33,000 city residents have yet to return to their homes, Mr. Kemins estimated. Some are abandoning their flood-prone first floors and adding another story on top, he said, or elevating the entire house. Others, like the Blumenfelds, are starting over and building higher. To date, some 200 households have applied for permits.

These are all expensive solutions, but they don’t seem nearly as expensive when you consider that under the Congressional Biggert-Waters Flood Insurance Reform Act of 2012, those who have houses that sit four or more feet below the local sea level threshold, or “base flood elevation,” as FEMA refers to it, could have annual premiums rise to as much as $9,500 a year — for flood coverage alone. Houses raised well above the threshold, on the other hand, will generally pay less than $500.