The city agency overseeing the reconstruction of homes wrecked by Hurricane Sandy is quietly rolling out a radical new approach to the rebuilding. NY1's Amanda Farinacci filed the following exclusive report.

Contractors labored in freezing temperatures and snow Tuesday, rebuilding a Midland Beach home damaged four years ago by Hurricane Sandy.

Every day counts - the city's Build It Back program already is behind schedule and way over budget.

"The process has been slow. The cost has been astronomical," said City Councilman Steve Matteo.

Hoping to rein in costs, the city is exploring a new rebuilding option: Modular homes.

"I don't think I'd like that type of a home. It's like living in a trailer," said one Staten Island resident.

Sources tell NY1 the de Blasio administration plans to scrap the reconstruction of 20 houses on Staten Island, and another 20 in Queens, and instead replace those homes with prefabricated units.

It's a pilot program the city believes will significantly lower costs.

Union masons hired by the city would build large block foundations. The prefab homes would sit on top. It would eliminate the cost and construction problems re-building entire homes with union labor and placing them on so-called stilts - steel columns designed to elevate the homes above the flood plain.

"It's probably a good example of what, God forbid, another sandy hits, maybe this is, will show that this is a valid option of rebuilding going forward," Matteo said.

The idea of building prefabricated homes is not new. In fact, just months after Hurricane Sandy, local officials pushed for it. What's unclear is why the city didn't embrace it before it began the expensive process of rebuilding from scratch.

"Our streets in New Dorp Beach are very narrow. Will they be able to use those prefab homes in and get them down those narrow streets? There are a lot of issues that we definitely need to speak about," Matteo said.

City Councilman Steven Mateo says he is expecting to have those conversations in the coming days.

Build it Back would only say, "The city continues to explore options to construct the most challenging homes in these communities. One of these options is modular housing."