Hi John,
I recently ordered your plans for a 1 1/2 story cottage and so far am very impressed with the level of thought that goes into them. Reading them has been a low-cost education in home design and structure.
I am looking for a local architect in order to help me make some adaptations and to get stamps for California's seismic and energy compliance standards, but I have a quick question that I thought you may be able to help me with.
I intend to build a full perimeter crawlspace foundation as specified on page 1/C of your plans. I would like to make the foundation wall considerably taller than the 8" minimum that you specify. I'm thinking 20" from the outside soil to the top of the wall, but I was wondering whether making a taller foundation wall raises any issues that I should take into account.
Many thanks in advance,
-Mike
Mike:
No, in general UBC and IRC codes would not require any modification of that foundation detail for the taller wall you are requesting. As the walls get closer to becoming a basement and are resisting outside backfill pressures then horizontal and vertical reinforcement are normally called out. Such a "full basement foundation" is shown only in my Universal Cottage plans.
A two foot high crawlspace would not normally need this however.
Since you will be having an engineering review for local seismic loads, there may be some extra hold-downs and perhaps some additional rebar called out for the foundation. These items are unlikely to add greatly to the cost.