In the Know

Historic Structure Reports

Rehabilitating a historic building often requires a little extra care and finesse. In this series, we discuss how honoring traditional materials and construction techniques can make a building shine.

This post discusses the anatomy of a Historic Structure Report and why the report is an important resource for the owners of historic buildings, especially when repairs or improvements are being considered.

A Historic Structure Report (HSR) is a critical preservation planning tool that provides detailed information about a property’s history and existing conditions using a combination of archival research and architectural investigation/documentation. The HSR is typically prepared in advance of a large-scale restoration/rehabilitation project in order to guide the scope of work by recommending appropriate conservation strategies and techniques for the building’s historic fabric.

Remember the TV show “This is Your Life”? That’s what an HSR is for a building.

 An HSR is tailored to individual projects and can be as long or short as the scope of work requires. Typically, the HSR includes:

• Detailed discussion about the history of the property
• Physical description of existing conditions
• Timeline of alterations
• Evaluation of significance
• Assessment of existing fabric and conditions
• Recommended strategies for long-term maintenance, preservation and/or restoration of historic building fabric and features

 

Property History

A thorough history of the building and its context is vital for understanding its significance. In addition to the building’s history, the HSR should include information about the architects, builders, and any significant persons or events historically associated with the property. Archival research materials such as National Register nominations, survey reports, newspapers, and correspondence can provide useful information.

 

Existing Conditions

A narrative description of the building’s current physical appearance familiarizes the reader with the property. The physical description should provide a big picture overview of the building. A later section will describe the condition of specific building elements.

 

Archival Research, Architectural Investigation & Materials Analysis

Archival research, along with architectural investigation and materials analysis, helps develop not only the history and significance of a building but a timeline of its evolution and alterations. Historic plans, photographs, Sanborn Fire Insurance Company maps, and building work permits can all be valuable sources for discovering how the building looked originally; what, if any, changes or improvements were made; and when those changes occurred. Architectural investigation and materials analysis can be used both to further classify those alterations and evaluate the building’s existing conditions.

Architectural investigation is the process of examining a building’s architectural fabric in order to identify its original elements, chronology of alterations, and current physical condition. Materials analysis refers to the scientific testing of building materials such as finishes, mortar, wood, metal, etc. The tests can determine original paint colors and the type of mortar, wood, or other construction materials used throughout the building. Comparing a building’s finishes and construction materials, such as trim, molding, and paint colors, over time and its different types of mortar or masonry can pinpoint areas of change.

 

Evaluation of Significance

Synthesis of archival research and architectural investigation/materials analysis provides insight into which construction materials, spaces, decorative elements, and finishes have architectural or historic significance and helps to determine the period of time in which the features achieved significance. An evaluation of the property’s significance discusses which features of the building are historic and defines a period of significance, generally the length of time when a property was associated with important events, activities, or persons.

 

Conditions Assessment

The conditions assessment is crucial to the HSR. After identifying a building’s historic fabric through archival research and architectural investigation, it documents and evaluates the current condition of building materials and systems. In most cases, a narrative description of existing conditions along with thorough photographic documentation of the building’s interior and exterior is sufficient. However, if the HSR is written in preparation for architectural changes, measured drawings of the building’s existing configuration should be produced. The conditions assessment also discusses causes of deterioration along with results from any materials analysis and recommendations for conservation treatments.

Combining all of the information gleaned from the HSR’s components allows the property owner to prioritize repairs and to tailor a maintenance plan to the building’s significant spaces and features. Priorities and maintenance techniques may shift over time as the building’s use changes or if additional research and documentation reveal new information about its history. An HSR should be a “living document” that is reviewed and updated regularly to reflect the current condition and function of the resource. Compiling comprehensive information about a property provides a robust narrative of the its architectural history and ensures that all aspects of its development are considered when making future changes.

In the next post, we’ll look at a case study that illustrates how an HSR can be used.

 

Comprehensive Conditions Assessment for the Weston Bend State Park Historic Tobacco Barn, Rosin Preservation, 2016 https://rosinpreservation.com/portfolio_page/weston-tobacco-barn/