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CALIFORNIA'S SHBC: Seismic and Structural Upgrades under the SHBC

Earthquake damage repair and mandated seismic upgrading have generated a great deal of discussion regarding the appropriate degree of intrusiveness of seismic work vis-a-vis the latitude available under California's Historical Building Code (SHBC) which governs all qualified historical buildings. Technology with regard to archaic materials and methods of construction is rapidly advancing. Specific site seismicity, materials testing and stress analysis are tools which continue to be refined, permitting much more informed structural evaluation than in the past. The SHBC permits and encourages these new technologies in addressing the retrofit of historic resources. It must be recognized however, that, while the SHBC is a call for making the least intrusive modifications necessary to retain the viability of California's historic resources, a justifiable case can readily be made that, when addressing seismic stability, this is not a call for the barest minimum of work, but rather a call for the most prudent balance of intrusion and preservation that will effect the highest reasonable level of protection against future significant damage or loss of the historic resource.

In California, a building's ability to resist seismic activity is a key factor in its continued viability. It must also be acknowledged that there is a hierarchy of values of historic resources, which can justify, for those buildings of great historic significance, a highly intrusive seismic upgrading program. The most notable example of this is California's State Capitol which is, essentially, a reconstruction, albeit an extraordinarily well documented one. Thus, if one were to look at the comparative cost-benefit ratio, there is greater value to a community in a historic resource, hence there is justification for greater expense to protect that value.

The protection, preservation and continued viable use of California's historic resources demands of us the application of today's technology to yesterday's construction materials and methodology, recognizing and utilizing the strengths inherent in archaic materials and methodologies which have permitted them to withstand the test of time. Building on this foundation, and supplementing it with the best in seismic resistance technology, we are committed to incorporate a reasonable level of seismic resistance in the least intrusive manner.

It is rationally indefensible to misuse the SHBC in order to fund, at a lower level than its non-historic peers, the earthquake repair of a structure identified as an historic resource. And it is a misreading of the SHBC to interpret it as a license to merely "paint the cracks" of historic buildings. The SHBC's commitment is to the preservation of these resources, by implementing, on a case-by-case basis, the solution which best fulfills the unquestionably long-term goal that word implies.