Introduction to the California Historical Building Code

California is unusual in that it has developed and adopted a building code specifically intended for historic preservation. The California Historical Building Code (CHBC) was developed nearly forty years ago in response to the problem that “restoration is frequently made difficult by the unnecessarily rigid interpretation of building…codes”. Despite the passing of significant time, many engineers and architects are still completely unaware of the existence of the CHBC and its context in the suite of California codes. Even those aware of its existence are sometimes prone to misconceptions regarding its content and use. This paper will discuss the history of the CHBC and its purpose and intent. A summary of use of the CHBC will be presented, along with its application — and its differences with the regular code — for repair, additions, and alterations; change of use; and seismic upgrades. This is the first of two companion papers that address the CHBC. A complimentary paper provides examples of beneficial use of the CHBC and cautions regarding potential misuse.