ALBANY — Gov. Andrew M. Cuomo is proposing to spend as much as $400 million to purchase homes wrecked by Hurricane Sandy, have them demolished and then preserve the flood-prone land permanently, as undeveloped coastline.

The purchase program, which still requires approval from federal officials, would be among the most ambitious ever undertaken, not only in scale but also in how Mr. Cuomo would be using the money to begin reshaping coastal land use. Residents living in flood plains with homes that were significantly damaged would be offered the pre-storm value of their houses to relocate; those in even more vulnerable areas would be offered a bonus to sell; and in a small number of highly flood-prone areas, the state would double the bonus if an entire block of homeowners agreed to leave.

The land would never be built on again. Some properties could be turned into dunes, wetlands or other natural buffers that would help protect coastal communities from ferocious storms; other parcels could be combined and turned into public parkland.

In the aftermath of Hurricane Sandy, which swept through the region on Oct. 29, Mr. Cuomo has adamantly maintained that New York needs to reconsider the way it develops its coast. He has repeatedly spoken, in blunt terms, about the consequences of climate change, noting that he has responded to more extreme weather in his first two years as governor than his father, Mario M. Cuomo, did in his 12 years in the job. Last month, in his State of the State address, he raised the prospect of home buyouts, declaring “there are some parcels that Mother Nature owns.”