1 Build Your Own House explains the pros and cons of a crawl space foundation. 2  A full basement foundation for an average home can cost $13,000-$30,000 or more, depending on the width and height of the walls, and whether utilities, windows or other features are included. Typically footers are poured along with short walls that support the home; some crawl spaces provide only 16-18 between the bottom of the floor joists and the soil, while others are tall enough to crouch inside. 2  Build Your Own House explains the pros and cons of a crawl space foundation.