Want to stay on the coast? Homeowners weigh post-Sandy elevation.

A year ago August, the storm surge from tropical storm Irene pushed six inches of water through Fred and Lisa Clarke's two-story beach cottage on the banks of the Norwalk River in Connecticut.

Just after the Clarkes completed getting the house back the way they wanted it, superstorm Sandy pushed 18 inches of water through their living room.

For the Clarkes, it's been two floods and lots of dirty work and tears.

"I think we're going to elevate the house," says Ms. Clarke, as she looks at the bare planking on the great room floor. "We just don't know how high we will have to go."

The Clarkes are among tens of thousands of homeowners whose abodes were flooded by Sandy and who are now trying to figure out a long-term solution.

Do they rebuild thinking the storm was just a freak of nature and not likely to happen again? Do they reach deep into their pockets to hire architects and contractors who can try to stormproof their homes? Or do they throw in the towel, allowing Mother Nature to take over their property?

The answer is a complex mix.

The Federal Emergency Management Agency is likely to review where the floodwaters ended up to see if it needs to change the agency's approximation of the boundaries of a 100-year flood. Local officials will wait until that FEMA verdict comes in before looking at zoning. Still, in any event, local officials are likely to give some kind of green light for those homeowners who decide they want to rebuild.

"Barring imminent health and welfare issues, no one will prevent them from rebuilding," says Marc Roy, a former FEMA official who is now an adjunct professor of disaster management at Tulane University in New Orleans.

But should they?

Some experts in flooding say residents in low-lying coastal areas that flood should consider moving to higher ground.

"After a couple of floods, if people used common sense, they would just get out of there," says Orrin Pilkey, a professor emeritus at Duke University in Durham, N.C., and an expert on coastal sea-level rise. "I would not just patch up the holes and go back."

But people are often driven by the love of their homes or communities and want to return.

In New Orleans following hurricane Katrina, for example, some residents in areas that were under 18 to 20 feet of water, such as the Lower Ninth Ward, have rebuilt. In some cases, they are now protected by higher and better levees, which held when hurricane Isaac came through this August.

Clarke also has strong links to the area where her home flooded. In a brief drive around the neighborhood, she stops to say hello to a distant relative, who is cleaning up after the storm. She remembers her grandmother's home a short distance away in Harbor View – a community also flooded by the storm. And she and her husband often launch kayaks from their backyard and paddle around the harbor.

But for most homeowners, a key factor in determining how to rebuild will be where FEMA decides there might be flooding in the future. The agency is in the process of revamping its flood maps by using technologies such as computer modeling and lasers from space.

"Some of the communities said, we don't believe this new technology, raising the lines to a degree we did not see happen in Katrina," says Mr. Roy, who is also associated with the charity organization International Relief & Development, based in Arlington, Va. "Why build to higher marks?"

A main reason to build to higher flood lines is the loss of financial assistance in case of another flood. FEMA does provide grants to affected households, including some that don't have flood insurance, but to be eligible for future assistance, families then have to purchase flood insurance for a number of years and in many cases abide by state requirements for building codes.

"When faced with the loss of funds, most people take the economically prudent course and incorporate the standards," Roy says. "If you build to the new standards, you get the best insurance rates, and you have the best chance to weather the next storm."

Under federal flood-insurance regulations, if a flooded house is in an area where the waves that inflicted damage were larger than three feet and the home requires more than a 50 percent repair, the homeowner is likely to have to rebuild on a piling foundation and elevate the home in some manner, says Spencer Rogers, a coastal erosion and construction specialist who is involved with North Carolina Sea Grant, which works on coastal issues.

Pilings need to be deeply embedded so that erosion won't weaken them. And the house has to be high enough so a wave won't hit it.

"A very small breaking wave can destroy a building very quickly," Mr. Rogers says. "Added height for the foundation is the only safety factor."

Mr. Pilkey has found in his studies that houses that were built two feet above the 100-year flood level have always survived. "That seems to be the magic number. Everything above that was safe," he says.

In Norwalk where the Clarkes live, officials anticipate that FEMA will require buildings to be elevated about another foot as a result of Sandy.

The Clarkes' house, which is already about seven feet above the mean high tide, may have to be elevated to 14 feet above high water, depending on the FEMA changes, says Joseph Delallo, an official in the building-code enforcement department.

"You are not going to stop the water," Mr. Delallo says. "If you elevate the house, then you don't have to worry about it."