Functionally Related Structures

Department of the Interior regulations governing the historic preservation tax incentives program state: 

For rehabilitation projects involving more than one certified historic structure where the structures are judged by the Secretary to have been functionally related historically to serve an overall purpose, such as a mill complex or a residence and carriage house, rehabilitation certification will be issued on the merits of the overall project rather than for each structure or individual component. [36 CFR Part 67.6(b)(4)]

The NPS has developed general criteria to help define when buildings are “functionally related historically.” The list is by no means exhaustive and properties need not meet all the criteria to qualify as “functionally related historically.” 

Some very large and diverse properties listed in the National Register as historic districts were designed to function as self-contained communities. Large military bases and medical, university, and corporate campuses are some of these properties. These properties generally may be treated as multiple projects for the purpose of certification. In these large and diverse properties, the NPS will determine which structures, sites and environments functioned in effect as separate properties and which structures, sites and environments were “functionally related historically.” 

In some limited situations, the rehabilitation of multiple buildings that were functionally related historically may be treated as separate projects for the purpose of certification. The NPS has developed guidance and examples to assist applicants in determining whether the guidance applies to a specific project.

Program regulations also specify the limited circumstances in which demolition of a component of a multiple-building project may be approved, and these should be addressed in the description of the project in the Part 2 application.

Last updated: November 6, 2023