We, as engineers are asked to perform a variety of assessments and observations during a site visit. In two cases shown below, we assessed existing foundations with a basement underneath a residential structure.
Per Los Angeles City Code brick or rock foundations are not permitted. These foundation types of foundations which were common up to 1910s, are not permitted due to earthquake requirements. In today’s code, reinforcement (rebar) is required to be used in construction of foundation.
If you are going to do remodeling or an addition to any structure with such a foundation, you will be advised to demolish, remove, and replace the existing foundation with a concrete foundation. If there is an existing basement, the basement walls need to be changed as well to either Concrete Masonry Block (CMU) or Reinforced Concrete Basement walls.