FEMA wants the classic "Base Flood Elevation" (BFE) to be what they want you to elevate to. But in some areas they want BFE plus 1 foot (BFE+1). 

HUD demands that new construction be at Base Flood Elevation plus 2 feet and has made it's determination based on measuring mudlines on buildings. First it was BFE matching FEMA maps then Super Storm Sandy prompted HUD to go to BFE+1 foot because BFE is where the mudline was measured at. 

HUD again measured the mudline in Louisiana from the Amite river and found that BFE+1 would have had wet floors so they upped the elevation in December of 2016 to BFE+2 feet for all new construction. 

While FEMA and HUD were suggesting and demanding increases your local municipality was listening to those squeaky wheels that didn't want to elevate so the locals remained at BFE if anything. 

With new codes coming in 2023 upgrading most states from codes written in 2015 you'll find that it's all about energy, safety and disaster mitigation for most of us building new homes. 

New code is going to come in at BFE + 1 foot but I wouldn't stop there if you are near any body of water that can flood your home. 

Remember, HUD currently wants BFE + 2 feet and FEMA wants BFE + 1 foot but soon you'll have the National Flood Insurance Program asking for a solid BFE+3 feet if you want low rates living in a special flood hazard area. 

So when you're talking to your builder, ask them what the highest measured mudline is for floods, what the highest recorded wind and the most rain in a measured period of time. Once you have that information you can design a foundation that will keep your nice floors above the muddy waters that oh so often reach our floors more than 1% per year or more than a few times every 100 years. 

My suggestion is to build up from BFE adding 3 good feet and build by columns so you don't displace the flood waters that are heading your way. Here's a little known fact, HUD sees floodways and special flood areas as protected natural watershed and habitat that should have no construction whatsoever in those areas. But if you're going to build, they advise to elevate but not with fill dirt, elevate with a pier and beam designed foundation. 

Cost of building will increase about $32/sf for elevated homes. 

Cost of flood insurance will be lower than your neighbors that didn't elevate when they could.

It's up to you, pay to mitigate or live in a trailer for 6 to 8 years while you try to rebuild from a disaster. 

My vote, Base Flood Elevation + 3 feet as a minimum standard to reduce insurance costs and damage to your new home. 

Research Resource

• Flood Maps 
• Example flood area Louisiana