A retaining wall is a structure that holds earth or other fill on one side and keeps it from moving beyond the wall.
Retaining walls are used to keep earth behind the wall from eroding, and to add additional level space to a sloping lot. Retaining walls are usually in scope of a home inspection only insofar as their failure might negatively impact the house. In practice, many home inspectors inspect most or all retaining walls on the property because repair and replacement of retaining walls can be expensive, and because clients often expect inspection of retaining walls. Home inspector’s reports should disclaim retaining walls not inspected, and should recommend that they be inspected.

A retaining wall may be any height. Wall height is often measured from the top of the footing. Retaining walls more than 4 feet tall with no horizontal support at the top, and retaining walls that retain a lateral load, may require an engineer approved design and a permit to construct. Retaining walls less than about two feet tall are sometimes called landscape walls or garden walls.

Diagram displays a retaining wall without top support.


Diagram displays a retaining wall with lateral load.


Photo of a wood retaining wall supporting a lateral load wall that is likely too tall for wood. The wall is near failure and bowing outwards.


Photo displays a lateral load on a failing wood retaining wall