Consider The crawl space when buying your next house:
Many houses with a crawl space have the traditional crawl spaces with plastic overing the earth, and insulation installed between the floor joist. These spaces require venting, the vents are spaced on opposite sides of the foundation above grade. This allows the air to flow through the crawl space, reducing the possibility of mold and condensation. An alternative to this type of construction, and is becoming more and more popular is the conditioned crawl space. The conditioned crawl space has insulation on the perimeter walls and not in-between the floor joists, This also eliminates the foundation vents so you no longer have outside air flowing through the space. With the crawl space conditioned the floor above is warmer to the touch in the winter. You will also experience better energy efficiency, improved air quality, improved structural longevity, and the Equipment in the crawl space is better protected. One of the best features, in my opinion, is the the crawl space in much nicer to move around in to service any equipment such as HVAC or water filtration.