by the Center for NYC Neighborhoods
If you have a basement or sub-ground crawlspace, you’ll need to fill that in, too. You’ll need to move all the utilities above the Design Flood Elevation or place them outside in an elevated structure. You will also need to make the first floor “unfinished” (with no drywall) and add flood vents or openings below the Design Flood Elevation for your property. This can be an expensive strategy, but it can significantly reduce your insurance premium and risk. It also may mean giving up a significant portion of your home’s living area, which is an important trade off to consider when deciding whether or not to adopt this mitigation option.
If you abandon the first floor of your property, you effectively raise the elevation of your home’s lowest living-space, or “lowest floor” for rating purposes, which minimizes your premium.
Abandoning the first floor of your home can raise it to or above the BFE. This increases the likelihood it will be protected from flood waters, keeping your property and your valuables safe from damage.
Abandoning your first floor will require temporary relocation as well as additional construction to move your mechanical equipment and appliances, and to build an alternate entrance to your home after your first floor is filled in.