Dating Buildings

The Center for Historic Preservation receives many requests for assistance in determining the date of construction (or of later alterations) for historic buildings. Traditionally such dates were derived through documentary research and/or architectural stylistic analysis. However, these methods sometimes prove inadequate, especially for vernacular buildings, which often were not well documented and usually lack identifiable formal styles. In such cases, relevant dates can sometimes be determined through examination of construction technology.

In recent years scholars have begun to better understand the evolution of construction technology. This knowledge of construction practices in use at specific periods of history provides the basis for dating historic buildings. As a result of the Industrial Revolution, the evolution of construction technology progressed at a rapid pace from the late 18th to the early 20th century, and buildings of this period can often be dated by examining the material evidence of construction methods used to build them. The same dating methods also provide a powerful tool for estimating dates of later alterations and/or additions to historic buildings.

The following material evidence of historic building construction can be used for dating purposes: