Section 106 Case Studies Guidance

Section 106 Case Studies**

Guidance provided by the State Historic Preservation Office (SHPO) of Michigan



A case study is a document that outlines a federal agency’s efforts to develop and evaluate alternatives or modifications to a project that could avoid or minimize adverse effects to cultural resources. The case study provides a record of an agency’s due diligence to carefully consider the impacts of its actions upon cultural resources. The document may also reveal previously unidentified but feasible alternatives that will avoid impacts altogether.


A case study should identify and evaluate alternatives to avoid an adverse effect, including the “no build” alternative. The case study should provide sufficient data and supporting arguments to demonstrate to the cold reader why a particular alternative is or is not feasible. The case study should start from the premise that a problem needs to be solved (e.g. high density traffic) rather than argue for a specific project (e.g. a new road). Data should not be manipulated to support a predetermined outcome. Rather, the best alternative or set of alternatives should arise from the data itself.

When considering alternatives, it is important to remember the role of the SHPO in reviewing the case study. The SHPO is a mandatory consulting party in Section 106 consultation, per the National Historic Preservation Act of 1966, as amended. The SHPO also has a broader role in Michigan to identify, evaluate, register, interpret and protect the state's cultural resources. Therefore, while the SHPO must take many factors into account in reviewing the case study, the welfare of the resource is always foremost. Even if the outcome is still adverse, the most successful and convincing case studies will give exhaustive consideration, within reasonable limits, to the welfare of cultural resources.

The types of data to include in the case study will vary according to project, agency and context, but may include the following:

  • statutes, regulations or agency policies that may affect a particular alternative;
  • agency financial information;
  • demographic or geographic information;
  • traffic or visitor counts;
  • structural and engineering reports;
  • cost analyses

In general, if the case study argues for or against a particular alternative, then all of the factors involved in that decision should be explained in some detail with supporting facts. If, for example, the case study claims that rehabilitation of a historic building is cost-prohibitive to your agency and the study argues for demolition, then the case study must provide a professional assessment of building’s condition and a cost analysis of rehabilitation vs. demolition and new construction. An argument is only as credible as its source. Therefore, qualified professionals in a particular relevant field (e.g. a historic preservation architect in the case of historic building rehabilitation) should provide such information and those professionals should be identified in the case study.

Among the alternatives considered, one should always be the “do nothing” or “no build” alternative. An agency should analyze this alternative with the same rigor that it gives to the other alternatives. Other alternatives examined will depend upon the agency and circumstances, but we recommend that several options be considered. Too narrow a focus may result in the SHPO requesting consideration of additional alternatives. The SHPO may request additional information or clarification of points in a case study until it determines the document is satisfactory and the agency has made a competent case for a particular alternative. Using the example of a building demolition described above, perhaps an agency does not have the funds to rehabilitate the building and is using that fact to support its argument for demolition. However, could the building be sold to another entity that might rehabilitate it, or mothballed until a sale is possible? What are the arguments for or against these options?


There is no required format or length for a case study. However, a good case study will state the problem to be solved and will outline, with supporting data, at least three alternatives the agency has considered in order to solve the problem. The agency will then conclude with an argument for its preferred alternative. The agency should provide a strong case for the preferred alternative, particularly if the alternative will result in impacts to cultural resources.

An agency may submit as a Section 106 Case Study an Environmental Assessment (EA), Environmental Impact Statement (EIS) or similar document that has been completed in satisfaction of other regulatory requirements if that document meets the requirements outlined above.


Contact the SHPO’s Cultural Resource Protection Staff:

State Historic Preservation Office
Michigan State Housing Development Authority
735 East Michigan Avenue
PO Box 30044
Lansing, MI 48909

Telephone: 517-335-2721


** This document was prepared to assist federal agencies and their delegated authorities in their compliance with the regulations implementing Section 106 of the National Historic Preservation Act of 1966, as amended (36 CFR Part 800). Case studies may be necessary even when Section 106 is not applicable, such as when Michigan law and guidelines require SHPO review. The SHPO recommends that the concepts and practices outlined in this guidance be followed any time a case study concerning threatened cultural resources is required or desired.