Sister Foundations in Los Angeles

What is a sister foundation? This is a foundation that is poured against an existing foundation. Take, for example, a brick or rock foundation that is no longer performing as originally intended.

If that home is located in a historic region (such as areas of South Pasadena and Long Beach) where the look of the home cannot change, or if the home owner simply doesn’t want to alter the curb appeal of that home a “sister foundation” would be done.

A new reinforced concrete foundation is installed against the existing foundation to bring the home up to code. It is also important to mention that unreinforced foundations (river rock, brick, etc.) cannot be seismically retrofitted. In many circumstances when a homeowner is looking to retain earthquake insurance their carrier will need verification that the home meets todays’ current seismic building codes. The only way to do this with the aforementioned foundation types is with a “sister foundation”