Written by: Erich A. Kuchar, M.S., P.E.
California is unique in many aspects, but none more evident than building design. Ask any Architect or Engineer who has ever done a job in The Golden State and they will tell you from Architectural, Accessibility, Energy, and most importantly Structural, the state specific requirements are lengthy.
California follows the California Building Code (CBC) which is adopted from the latest International Building Code (IBC) from the previous year. Meaning that currently most states follow the 2021 IBC however California enforces the 2022 CBC. The CBC for the most part is the exact same as the IBC except as previously mentioned for critical changes in Accessibility, Energy, and more strict regulation of Structural.
Structural design in California is governed, no surprise, by seismic design. That is even taken farther since more then 90% of California is classified as Seismic Design Category (SDC) D. Now what makes that so important… well A LOT. Almost every structural code and regulation breaks down seismic design principles to SDC A through B and SCC C through F. Since almost all of California is in the SDC C though F, ALL projects require a current code, site specific, stamped and signed Soils Investigation report. This report must break down soil parameters and seismic design parameters for the structural design to follow. This of course means you cannot simply follow the code minimums for items but need to follow the site-specific actual parameters.
Another challenging item for out-of-state designers and product manufacturers is that a vast majority of pre-approved/ pre-engineered items are not valid in California and must have items be submitted with full construction documents and calculations to the city in which the project is for review and approval by that Building Department. A lot of ICC approved, or similar, products do not go through seismic testing showing response to cyclical testing but just wind testing. What does that mean in simple terms? Basically, most products, like windows, patio covers, modular shear panels, pre-engineered structures, etc., when tested to get a pre-approval only get tested for wind pressures and SDC Categories A though B and sometimes A through C. The reason for that is the testing and pre-approval is cheaper AND most products fail in cyclical testing, which is loaded and unloaded and loaded and unloaded, etc. over and over again. Think of bending a paper clip back and forth until it gets weaker and breaks.
This however is not limited to pre-engineered items but also many lateral resisting elements found in the ASCE 7-16 are Not Allowed or severely hampered once you are in SDC D though F which can add significant cost to projects as a cheaper Ordinary Steel Moment Frames, for example, that you could have used in another state would not work in California for most projects. Most code approved lateral resisting elements will have penalties due to the higher seismic loading.
In short, the challenges to developers and owners in California is that even though it’s the West Coast it is Not the Wild West in terms of design and plan review and permitting. There are no shortcuts or quick routes for projects. The same exact building that was submitted in another state with minimal detailing and little to no calculations will need to be fully detailed and full and complete calculations submitted resulting in dozens of extra detail sheets and a much more comprehensive review process to ensure complete and full compliance of the California Building Code are met. This results in a higher scrutinized and ultimately more structurally sounds project.