Are you looking to build a home on a crawlspace? A typical crawlspace is a damp dark place under your home that can have an effect on your homes efficiency, comfort and your health. Damp dark places can be a prime location for mold growth. For decades builders have tried to combat these conditions by covering the ground and venting the space to the outside. Code requires the ground to be covered with a 6mil polyethylene (or plastic as we all like to call it) That "plastic" only slows down the moisture it does not block it completely and the ground seldom gets fully covered or sealed to the walls so how exactly do you stop the moisture from getting to your floor? Once moisture is in the space, you try to get rid of it by ventilation. Its hard to lower the moisture level in the summer when the humidity outside is 70% or higher. And when the humidity is low in the winter you have to close the vents in order to keep your pipes from freezing. How does any of that make sense?
The solution to a better crawlspace is to seal it. That means no vents and requires a vapor BARRIER. 6 mil is not a barrier. We use a thicker product and seal it to the foundation walls to block moisture and/or any other contaminants from getting in from the ground. The next step would be to insulate the foundation walls and make the crawlspace a semi-conditioned space. That makes a great location to install heating and cooling equipment inside the insulation envelope of the home. That makes your equipment much more efficient and can result in smaller, less expensive equipment!
A clean, dry, humidity controlled crawlspace is a great start to a healthy home!