Homeowners and builders make decisions about which type of foundation to use by gauging cost, needs/desires, and soil and weather conditions. If you have high water tables then it may not be possible to have a basement. If your land has shallow bedrock or boulders then it may be more costly to dig a basement. If you have a sloping lot it may be difficult to use a slab foundation. If you have a cold climate then you may need to dig down at least four or more feet to put the home’s footings below frost level. If you have to go at least four feet deep then it may be worth spending some extra money to dig a few feet deeper and have a full basement. Also, it is easier to install and maintain mechanical systems in basements (compared to a crawlspace). Your builder can help you determine what type of foundation is best suited for your area.
The choice of foundation is also affected by personal preferences and costs. Basements can add thousands of dollars to the cost of a home compared to the cost of a crawlspace. However, when you consider the extra useable space created by a basement it is some of the cheapest square footage space of a home. If you are tight on funds and can’t afford the basement then it may be a good idea to find a slightly smaller plan and use the savings to create a basement. You’ll end up with a lot more storage space and potential living space by doing this.