I agree with JDS; there are several methods of creating a true, conditioned or unconditioned crawl space. That being said, the cost of a full basement over a crawl space is so incremental in my area that I'd opt for the basement - even if I didn't use it - for resale value. There are so few slabs or crawl spaces around here that it really negatively impacts selling prices.

So new search terms, incapsulated, conditioned, unconditioned, unvented. Basically you are saying there are two types of crawl spaces? Incapsulated/unvented and unconditioned/vented? How do pump air into an unvented crawl space? Not sure I get that part. Anyway I will do more searching with this. As for basements, yes this state normally has basements. And my mother used to have to wet vac hers all the time till she ponied up 10,000 for a french drain. My sister is also dealing with a wet corner now. For resale I worry about not having one but as a senior I'm over it. Anyway, this is a lake lot with high water tables.

The 2012 International Residential code says:

R408.3 Unvented crawl space.
Ventilation openings in under-floor spaces specified in Sections R408.1 and R408.2 shall not be required where:

1. Exposed earth is covered with a continuous Class I vapor retarder. Joints of the vapor retarder shall overlap by 6 inches (152 mm) and shall be sealed or taped. The edges of the vapor retarder shall extend at least 6 inches (152 mm) up the stem wall and shall be attached and sealed to the stem wall or insulation; and

2. One of the following is provided for the under-floor space:

2.1. Continuously operated mechanical exhaust ventilation at a rate equal to 1 cubic foot per minute (0.47 L/s) for each 50 square feet (4.7m2) of crawlspace floor area, including an air pathway to the common area (such as a duct or transfer grille), and perimeter walls insulated in accordance with Section N1103.2.1 of this code;

2.2. Conditioned air supply sized to deliver at a rate equal to 1 cubic foot per minute (0.47 L/s) for each 50 square feet (4.7 m2) of under-floor area, including a return air pathway to the common area (such as a duct or transfer grille), and perimeter walls insulated in accordance with Section N1102.2 of this code;

2.3. Plenum in existing structures complying with Section M1601.5, if under-floor space is used as a plenum.

With the information and technology available today, wet basements should be a thing of the past, but if the water table is higher than the basement slab, it can be a losing battle. I hate relying on a mechanical thing such as a sump pump that can fail and leave you flooded. My BIL recently had this happen, and even though the sump pump had an alarm, this somehow failed as well. A qualified soil engineer should be able to tell you if ground water would be a problem on your particular lot. We went back and forth between basement and crawl, but on our sloping lot, the crawl would have been over 6' tall, so we built a fully insulated basement. With our small house, it's nice to have the extra space for storage, and the living space for the house could easily be doubled, if wanted by us or a future owner. If water had been a potential problem, we would have built on a crawl space.

I would search and ask on more technical sites such as greenbuildingtalk.com.

We built a new home 2 years ago and wanted one level but not a slab so we went with a 4' crawl space and poured a concrete floor. We used closed cell foam on the crawl space concrete walls and also the rim joists and have a conditioned crawl space. Our Geothermal HVAC unit is in the crawl and the plumbers and electricians loved the concrete floor for getting around and working on. In the long run a concrete floor wasn't that much more expensive than encapsulating the dirt floor and maybe even less expensive. The crawl space is always dry and we use it for storage.

I also have a slab in the crawlspace which is about 3'. It does have exterior venting, remains dry after 11 years, despite being waterfront with a high water table.

"With the information and technology available today, wet basements
should be a thing of the past, but if the water table is higher than the
basement slab, it can be a losing battle."

It's not hard to figure out what the normal water table is in an area, and build above it.

I agree with basements being the better choice. Hopefully there is enough topography to daylight sub-slab drainage opposed to relying on a pump, which tend to fail with the extreme weather that accompanies flooding or disaster events.

The comparison of basement versus slab is problematic as most basements have slabs. A frost wall or stemwall-with-slab is readily substituted for unvented crawlspaces and is probably a better construction practice in the eyes of most building researchers.

In my opinion new, vented crawlspaces should be illegal in humid climates like those east of the mississippi.

Detail it exactly like a basement, only shorter.