Photos: Hillary Clinton's life in the spotlight. Clinton waves to the media in January 1996 as she arrives for an appearance before a grand jury in Washington. The first lady was subpoenaed to testify as a witness in the investigation of the Whitewater land deal in Arkansas.
1 Adding a basement to an existing house can cost $30,000-$70,000 or more, depending on the size of the existing crawlspace or half-basement or if the house is on a slab foundation, and how much of the work is do-it-yourself and how much is done by contractors.
Typically the most expensive type of foundation, the full basement variety consists of a slab basement floor with stem walls that extend from the basement floor to the main level of the building and footers. Homeowners who choose this type of foundation will incur higher costs due to the need for deeper excavation. Grading and forms are also needed in addition to drainage, waterproofing and concrete reinforcements in the basement walls. People who choose a full basement foundation may pay as much as $30,000.