Nondestructive Evaluation for Historic Preservation
by Swanke Hayden Connell Architects and GBG, Inc.
Comprehensive planning and budgeting for a historic preservation project cannot commence without a detailed survey of a building's existing conditions. Information gathered during the documentation search forms the basis but cannot supplant the need for field inspection.
Those who plan to conduct the field investigation should first understand the existing construction. The original drawings, specifications, and historic research provide important information, but they may be inaccurate due to changesóboth during the initial construction and in later modifications.
Photographs taken during original construction or later modifications are especially useful in revealing concealed conditions. Researching other construction of the same period can also provide insight into the potential conditions and construction techniques.
In locations where building permits were not required when historic structures were first erected, there may be no archive or record drawings. Or the building's original drawings may no longer exist. In such situations, even more extensive field investigation and documentation may be necessary.
Visual Field Inspection
The field inspection involves examining all available existing conditions to identify the causes of deterioration and distress, and then documenting the findings. The inspection should address site features, architectural elements, and building systems, including structural, mechanical, and electrical.
Visual observations are generally documented in the form of drawings, field notes, and photographs. Copies of building drawings obtained during the documentation search can facilitate note-taking in the field.
This article is excerpted from Historic Preservation: Project Planning & Estimating, with permission of the publisher, R.S. Means Company, Inc.
Typical field survey documentation form from Public School 157 in Brooklyn, New York.
Image: Swanke Hayden Connell Architects
Nondestructive investigative techniques were used to determine construction methods and underlying conditions of Inigo Jones's 1621 Gateway at Chiswick Houses, Chelsea, England.
Image: GBG, Inc.
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