$ 139,004.75

Price may vary in your area. Inquire locally to receive more accurate cost information.

Realize that flood plains are subject to change. If you build the slab up 36', that doesn't guarantee that the floodplain won't change to 48' in 5 years. At which point, you will be responsible for flood insurance if you have a mortgage...and the value of your home will drop as someone can buy a similarly priced home for less per month due to not paying for flood insurance.

AE. Middle East?

Jim Mat-AE is a flood zone designation. It means that there is a 1% chance each each that the property could flood.

Here's a good blog on building in a flood plain:
https://www.projectsmallhouse.com/blog/2017/09/building-a-new-house-can-you-build-in-a-flood-plain/

Check with lenders in your area about flood insurance. Many underwriters in our area require flood insurance if any portion of the property is in a flood plain--even if the home isn't. You may be able to get an exemption if you get a flood elevation certificate after construction, but be prepared to pay for flood insurance during construction.

Why are you set on slab construction?

I have a thick slab but it still made sense - thick in one area, normal in other to match small slope of land. It was quite expensive compared to a totally flat slab but still cheaper than a crawl space.

At some point, the foundation type is a matter of cost and what the land needs. In your case, you need something other than a slab.

We call it a crawl space in my area but it is basically the same as a pier and beam. I tend to think when people use pier and beam, the assumption is that it isn't fully enclosed like a crawl space but I am not sure that distinction is necessarily correct.

I believe the savings on flood insurance is 25% for 1 foot above BFE, 50% for 2 foot, and 66% for 3 foot. I would shoot for 3 even if you aren't going to get flood insurance. Maps change. Water changes.

Like crawl spaces, pier-and-beam foundations raise the level of the structure above grade level.
However, they are different with respect to building code requirements, at least in jurisdictions where local codes are based on the International Residential Code (IRC.) Pier-and-beam foundations are not covered by the prescriptive building code so they need to be designed by a licensed professional engineer or architect. Pier-and-beam foundations also make the underside of the structure more accessible to birds, rodents, and insects, so you'll need to carefully consider how to insulate the structure and ensure the longevity of whatever material you use.

I would find another lot.

We lived in a condo for 30 years that was not even in a designated flood plain, but back-to-back 100 year rains created a temporary lake in our back yard and water leaked in around the basement windows so we had water on the floor that got sucked up the walls and also ruined the flooring.

They did some expensive moving of soil and laying of drain pipes, so the cost was spread out among about 80 condo owners, but in your case would be on your dime.

We never got 100 year back-to-back rains again while we were living there, so whether the problem was solved is unknown. But whenever we got heavy rains, I was never comfortable after that.

Anne