The key to preventing damage by moisture is to understand how water vapor interacts with building materials. Building materials absorb airborne water vapor and, if the material is cold enough to be below dew point, condensation occurs. We don’t want either condensation or absorption to occur, so there are two principles to adhere to avoid water damage, mold and mildew.
The best way to design a crawlspace that accentuates your building envelope and does not allow unwanted moisture into the home is to treat them as if they were miniature basement spaces. Crawlspaces should be insulated, sealed and all exposed masonry should be covered to prevent condensation.