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
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
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.
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.
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
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
Retention of later historic features that have
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
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.