A year after Hurricane Sandy, the United States still faces an enormous task to repair $60 billion worth of damage and improve resiliency before the next cyclone.

One of the costliest hurricanes in US history, Sandy ripped into the East Coast, affecting 24 states and paralyzing parts of New York, New Jersey and Connecticut.

More than 200 people were killed. Lower Manhattan was plunged into darkness for a week. New York, one of the financial capitals of the world, ground to a halt.

Businesses lost millions. The subway was flooded. Flights were cancelled. At least 650,000 houses were affected and power cuts lasted for months in some areas.

Schools and hospitals were disrupted, and fuel supplies interrupted after refineries and gas stations were hit.

Congress approved $60 billion in emergency relief, but bottlenecks, delays and insurance issues have made it difficult for many victims to rebuild shattered lives.

Steven Cohen, executive director of The Earth Institute at Columbia University, said parts of the response had been very good and other parts "pathetic."

"The best part was the emergency response and getting people out of harm's way and getting the New York City subway system up and running as fast as possible.

"The worst part has been the bureaucracy and the politics surrounding reconstruction. The fact it took months to get the aid package passed through Congress."

He called for a new incremental tax, such as on carbon or an increased tax on gasoline, to fund a permanent fund to respond more quickly to natural emergencies.

"We're going to see more intense storms, higher sea levels and we have to figure out ways to absorb the water... there has been a lot of progress on that."

That progress to date has seen the government buy homes in flood-prone areas, razing them and returning the land to wetlands to bolster natural defenses.

Government funds have also been made available for people to abandon their lower floor and build an extra story on top.

Businesses and homes are being encouraged to move utilities from the basement to the roof to minimize the prospect of power cuts in the event of flooding.

New York City, which has been praised for its response, has plans for microgrids and distributed general systems to generate 800 megawatts by 2030.

But not everyone is taking action.

Accounting firm Anchin, Block & Anchin says more than half 266 small businesses surveyed in the New York City area have not made preparations for the next storm.

"They haven't put anything in place in terms of preparation," Anchin partner Greg Wank told AFP.

Experts have praised plans unveiled by New York Mayor Michael Bloomberg detailing $19 billion of damage in the city alone, recommendations for rebuilding and improving the resilience of infrastructure.

But some have called for a more regional approach that coordinates recovery in all the worst-affected areas.

"The work ahead of us is enormous," said Illya Azaroff, a co-chair of the American Institute of Architects for Design Risk and Recovery.

"New York City, is moving in the right direction, it's the larger perspective that is our next challenge."

Homeowners are still confused about how to get their hands on available funds and how best to rebuild, and a more regional approach was needed.

"We're better educated about where we need to go but there are so many difficulties if you are the homeowner on how to build back better," Azaroff said.

One entire community on Staten Island, Oakwood Beach, decided to sell up when New York Governor Andrew Cuomo offered to buy back their ruined homes.

Filmmakers Jeff Reichert and Farihah Zaman, who are making a documentary about the recovery process on Long Island Beach, New Jersey, said they it been very moving.

They were struck by the little things, for example, the school that had to build its own sets for the prom because fundraising efforts had been expended on Sandy.

"And there have been smaller and day to day ripples that we weren't necessarily expecting but have been very poignant to watch," Zaman told AFP.

Reichert said "you assume once you don't see it on the TV anymore it's gone back to normal... it takes a lot longer than you could expect."