It is most common in areas of the country where the soil has high clay content. Problems with settling and inadequate subsurface drainage are often associated with this type of soil, therefore slab foundations are recommended. Using this type of foundation can also reduce construction costs. Unfinished Basement A basement foundation system is basically a deeper variation of a crawlspace foundation system. However, instead of a dirt floor, a poured concrete slab floor is utilized.
Most homes usually incorporate an interior staircase to access the basement.
Basement foundations become practical, when footings for a crawlspace foundation are required to be dug four feet or more. Also, if you are building in an area that is prone to severe weather, a basement is recommended. Sometimes called a daylight basement, this application is more practical for a sloping lot. Walkout basements, either finished or unfinished, have a portion of one or two of its perimeter walls exposed to the exterior with door access to the lower yard. Often an outdoor deck off of the house floor above is incorporated as part of the design.