Applying the standards

Standards for Rehabilitation

1. A property shall be used for its historic purpose or be placed in a new use that requires minimal change to the defining characteristics of the building and its site and environment.

2. The historic character of a property shall be retained and preserved. The removal of historic materials or alteration of features and spaces that characterize a property shall be avoided.

3. Each property shall be recognized as a physical record of its time, place, and use. Changes that create a false sense of historical development, such as adding conjectural features or architectural elements from other buildings, shall not be undertaken.

4. Most properties change over time; those changes that have acquired historic significance in their own right shall be retained and preserved.

5. Distinctive features, finishes, and construction techniques or examples of craftsmanship that characterize a historic property shall be preserved.

6. Deteriorated historic features shall be repaired rather than replaced. Where the severity of deterioration requires replacement of a distinctive feature, the new feature shall match the old in design, color, texture, and other visual qualities and, where possible, materials. Replacement of missing features shall be substantiated by documentary, physical, or pictorial evidence.

7. Chemical or physical treatments, such as sandblasting, that cause damage to historic materials shall not be used. The surface cleaning of structures, if appropriate, shall be undertaken using the gentlest means possible.

8. Significant archeological resources affected by a project shall be protected and preserved. If such resources must be disturbed, mitigation measures shall be undertaken.

9. New additions, exterior alterations, or related new construction shall not destroy historic materials that characterize the property. The new work shall be differentiated from the old and shall be compatible with the massing, size, scale, and architectural features to protect the historic integrity of the property and its environment.

10. New additions and adjacent or related new construction shall be undertaken in such a manner that if removed in the future, the essential form and integrity of the historic property and its environment would be unimpaired.

A rehabilitation project proposal must meet all ten Standards for Rehabilitation. Keep these issues in mind to help plan your work in a way that meets the Standards—prior to submitting an application for review.

Entirety of project
The project as a whole must meet the Standards. All work, both interior and exterior, the site as well as the building, is subject to review. There is no option to exempt any portion of the project.

Reversibility
See illustrated example
The "reversibility" requirement in attaching a new addition or installing adjacent or related new construction is important to understand. It means that if the new work were to be removed sometime in the future, the essential form and material integrity of the historic property would remain; however, a project cannot be determined to meet the Standards simply because unacceptable work is reversible, e.g., that it can be undone.

Cumulative effect
A project is determined to meet the Standards based on the overall effect of all work on the historic character of the building. In some cases, a single aspect of a project may be inappropriate, yet its impact on the character of the project as a whole is small enough that the project can be approved. In other cases, similar work can contribute to a denial if the project includes other inappropriate work items. The impact of numerous inappropriate treatments can be cumulative and result in denial.

Changes to non-historic features
See illustrated example
In general, it is the owner’s choice as to what or how much work will be undertaken on the historic building at the beginning of a project. There is no requirement that missing historic features be reconstructed, that intrusive or incompatible additions be removed, or that insensitive, non-historic changes be reversed. So, although a portion of the building may be left as it is found, if a change is made as part of the project, that change must be consistent with the historic character of the property. The new work—any change or replacement—must be compatible with the historic character.

Levels of change
See illustrated example
Rehabilitation, by definition, involves some change. The more important a feature or area is to the historic character of a property, the less it can be changed without damaging the character as a whole. On the other hand, aspects less critical to the historic character may sometimes be altered substantially with little effect on the overall character. For this reason it is impossible to say that a given treatment is always approvable or always deniable. A window that may be an acceptable replacement for a deteriorated rear window facing a narrow alley may not be acceptable for a window on the façade.

Retention of later historic features that have acquired significance
See illustrated example
Buildings change over time and, in most cases, a property’s significance is not limited to the date of its construction. Returning a building to its original appearance may not meet the Standards if it means the removal of later features or materials that have acquired historical significance over time. Features do not need to be original to be considered “historic” and character-defining. Even if a case can be made for returning a building to an earlier appearance, the work must not be selective or inconsistent. Rehabilitation must never result in giving a historic building an appearance that it never had at any point in the past.

Retaining and repairing historic material
See illustrated example
Every effort should be made to retain and repair historic material. However, the Standards acknowledge that sometimes deterioration may be so severe that replacement is the only reasonable option. When historic features and materials are replaced with matching materials, the change in visual appearance can be minimized.

But a building’s historic character is far more than simply a visual effect. The historic character is dependent upon the building’s material integrity, that is, its surviving historic material. If too much historic material is replaced with new material during rehabilitation, the historic character of a building is inevitably lost along with its material integrity. While new material can exactly copy significant features, material integrity itself can never be re-created. The precise replication of features with new materials may produce a building that looks like a historic building, but without retention of historic materials, the project will not meet the Standards for Rehabilitation.