Crawl spaces can be tricky! If not done properly moisture will be trapped and create mold and rotting wood. It also can become a breeding ground for wood eating insects. If you are trying to decide whether or not to purchase this home based on the crawl space you really need to get the advice of a professional home inspector who can look at the specific property and advise you what remediations are required to avoid all of these problems. Better to do this before you go to settlement.
I will be happy to recommend an excellent home inspector who can help you with this.
Coldwell Banker- Casa Bella Realtors
I'd guess that everyone who buys a house has a crawl space question. Recently I spent several days in my crawl space at my house of Stoney Creek in EHT. It should definately have a vapor barrier, some people go to a few inches of the edge some go all the way up the first block. I chose to go one extra step because I felt like the floors were cold, so I stapled up a 4 mil vapor barrier to the back side of the floor beams. I think it is warmer but I guess I'll have to wait until I see the gas bill in February. The most important function of the flow through air in a crawl space is to prevent moisture build up and thus "mold".