Planning Ahead
by M. Brett Gladstone
If you own an historic or architecturally valuable building in San Francisco, you may be able to bring it up to code and retain historic elements, with the help of the State Historical Building Code. This can sometimes also result in significant cost savings.
In the late 1970s, recognizing that the strict interpretation of existing building codes often destroys important features of older buildings, the California Legislature passed the SHBC. Observance of the code is mandatory for all agencies and jurisdictions in the state when dealing with “qualified” historical buildings.
The code applies to “any structure, collection of structures, and their associated sites deemed of importance to the history, architecture, or culture of an area, by an appropriate local or state governmental jurisdiction.” In San Francisco at present, the code applies to approximately 17,000 structures. This number includes designated state and city landmarks; properties on the National Register of Historic Places; buildings in existing and proposed historic districts; those listed in the Downtown Plan and in area plans of the San Francisco General Plan; buildings in the 1968 book survey Here Today; and buildings which the Planning Department rated in its 1976 citywide survey.
The intent of the SHBC is slightly different from that of the Uniform Building Code, which generally governs construction throughout the country. The intent of the UBC is the protection of life and property, in that order. (Other codes have also served secondarily to achieve other socially desirable goals, such as energy efficiency or accessibility for handicapped citizens.) Codes fulfill such intent by requiring certain ways of constructing new buildings so that walls are fire-resistant, for example, and properly insulated, or requiring doorways wide enough for wheelchairs to pass through. While the first priority of the SHBC remains the safety of building occupants, its second priority is preserving the historical and architectural features of the building. An alteration of a structure typically must comply with the UBC; however, if such compliance would result in destruction or loss of historic fabric, the SHBC offers an alternative.
The SHBC is less specific than the UBC, which gives builders fairly exact instructions. For example: “The top of handrails shall be placed not less than 34 inches nor more than 38 inches above the nosing of treads.” Or, “Every corridor serving an occupant load of 10 or more shall be not less than 44 inches in width.” The SHBC is performance-based, in that it allows the substitution of alternative means to achieve the intent of the exact prescriptive provisions of the uniform code. To use the SHBC, the equivalent performance of these alternative means must be demonstrable, as the SHBC is not supposed to compromise life safety.
Construction materials and methods of construction are obvious ways in which modern and historic buildings differ; for example, wood lath has fallen out of favor with modern plasterers. Compliance with the UBC would require replacing such historic materials with modern materials. The SHBC, however, permits repairs to existing structures using these older materials, often in combination with modern materials or construction methods, where it will result in preserving the authenticity of the historic structure.
The SHBC recognizes that some materials and methods of construction have survived quite a long time and have thus proven their claim for continued use in the building’s restoration or renovation. According to the SHBC, “Any method or material that is (or is similar to) the historic fabric of a structure that may have been dropped from present codes, was a known type of construction in the past, has served a useful purpose in the structure, and was as part of the historical structure…may be used or re-used in the structure.”
Modern construction materials are rated for their structural and fire-resistant properties as tested under laboratory conditions. The standardized production of many modern materials makes this testing highly predictive of how materials, when used in actual construction, will perform in a real-life emergency. A wall constructed of 2 x 4 studs covered with 5/8-inch gypsum board on both sides will have properties very similar to those of any other similarly constructed wall. Older materials no longer in general use have often posed problems for engineers assessing the structural strength of a building for seismic resistance or its resistance to the spread of fire.
Many historic materials never underwent such testing, and while they may perform as well as modern materials, there has been no rating to which building officials can refer. As a result, engineers can find it difficult to know the “shear value” (resistance to lateral forces of an earthquake) or fire resistance of a wall built a hundred years ago. To achieve desired seismic resistance, the SHBC assigns shear values to some archaic materials and permits their use in combination with modern code materials, on a case-by-case basis. In addition, the Structural Engineering Association of California has tested archaic materials and publishes a Blue Book, which assigns shear values to those materials. Using this information, engineers may devise creative solutions to building-safety problems that will allow preservation of existing historic fabric.
In the matter of fire safety, the SHBC requires buildings that do not conform to prevailing codes to install an automatic fire-extinguishing system and an approved, automatic fire-alarm system. Non-conforming interior wall and ceiling finishes such as Lincrustra may be resurfaced with an approved fire-resistant paint.
The opinions expressed in this article are those of the author and do not necessarily reflect the viewpoint of SFAA or the San Francisco Apartment Magazine. The information contained in this article is general in nature. Consult the advice of an attorney for any specific problem. Over the past decade, Gladstone & Associates has carved out an authoritative niche in San Francisco’s land-use landscape. M. Brett Gladstone is often tapped as a lecturer on a variety of topics, including real-estate legal issues, development entitlements, condominium law and planned developments. More information about the law firm’s work is available at www.gladstoneassociates.com. Copyright © 2005 by the San Francisco Apartment Magazine. All rights reserved.