A historic building is a product of the cultural heritage of its
region, the technology of its period, the skill of its builders,
and the materials used for its construction. To assist owners,
developers and managers of historic property in planning and completing
rehabilitation project work that will meet the Secretary's "Standards
for Rehabilitation"(36 CFR 67), the following planning process
has been developed by the National Park Service and is applicable
to all historic buildings. This planning process is a sequential
approach to the preservation of historic wood frame buildings.
 Historic wood siding exhibits rich and varied surface textures. They range from hand-split clapboards of short lengths with feather-edged ends (shown here), to pit or mill sawn boards which can be beveled, rabbeted, or beaded. Photo: NPS files. |
It begins with the premise that historic materials should be retained
wherever possible. When retention, including retention with some
repair, is not possible,then replacement of the irreparable historic
material can be considered. The purpose of this approach is to
determine the appropriate level of treatment for the preservation
of historic wood frame buildings. Standard 6 of the Secretary of the Interior's Standards for
Rehabilitation states that "deteriorated architectural
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..."
The Guidelines further caution against "removing or radically
changing wood features which are important in defining the overall
historic character of the building so that, as a result, the character
is diminished."
The planning process has the
following four steps:
1. Identify and preserve those materials and features that are
important in defining the building's historic character. This
may include features such as wood siding, brackets, cornices,
window architraves, doorway pediments, and their finishes and
colors.
2. Undertake routine maintenance on historic materials and features.
Routine maintenance generally involves the least amount of work
needed to preserve the materials and features of the building.
For example, maintenance of a frame building would include caulking
and painting; or, where paint is extensively cracking and peeling,
its removal and the re-application of a protective paint coating.
3. Repair historic materials and features. For a historic material
such as wood siding, repair would generally involve patching and
piecing-in with new material according to recognized preservation
methods.
4. Replace severely damaged or deteriorated historic materials
and features in kind. Replacing sound or repairable historic material
is never recommended; however, if the historic material cannot
be repaired because of the extent of deterioration or damage,
then it will be necessary to replace an entire character-defining
feature such as the building's siding. The preferred treatment
is always replacement in kind, that is, with the same material.
Because this approach is not always feasible, provision is made
under the recommended treatment options in the Guidelines that
accompany the Secretary of the Interior's Standards to consider
the use of a compatible substitute material. A substitute material
should only be considered, however, if the form, detailing, and
overall appearance of the substitute material conveys the visual
appearance of the historic material, and the application of the
substitute material does not damage, destroy or obscure historic
features.
In many cases, the replacement of wood siding on a historic building
is proposed because little attention has been given to the retention
of historic materials. Instead, the decision to use a substitute
material is made because: (1) it is assumed that aluminum or vinyl
siding will be a maintenance-free material; and (2) there is the
desire to give a building a "remodeled" or "renovated"
appearance. A decision to replace historic material must, however,
be carefully considered for its impact on the historic resource--even
when the model planning process has been followed and the appropriate
treatment is replacement.
Therefore, this brief focuses on the visual and physical consequences
of using a substitute material such as aluminum or vinyl siding
for new siding installations on a wood frame historic building.
These concerns include the potential of damaging or destroying
historic material and features; the potential of obscuring historic
material and features; and, most important, the potential of diminishing
the historic character of the building.
"Aluminum and Vinyl Siding on Historic Buildings" an Historic Preservation Brief
