Detail of restored roof; Link to Parknet
STANDARDS FOR RESTORATION AND GUIDELINES FOR RESTORING HISTORIC BUILDINGS
<photo>significant staircase, Department of Interior, Washington, DC

Identify    Protect    Repair    Replace    Remove   Re-Create

Identify, Retain and Preserve

-INTERIOR SPACES-

Recommend
Identifying, retaining, and preserving a floor plan or interior spaces from the restoration period. This includes the size, configuration, proportion, and relationship of rooms and corridors; the relationship of features to spaces; and the spaces themselves such as lobbies, reception halls, entrance halls, double parlors, theaters, auditoriums, and important industrial or commercial spaces.

photo of grand hall that possesses distinctive original features that would be preserved in a Restoration work project

Many institutional buildings possess distinctive spaces or floor plans that are important in conveying the significance of the property. This grand hall, which occupies the entire floor of the building, would be retained and preserved in a Restoration work project. Photo: NPS files.

Not Recommended
Altering a floor plan or interior spaces--including individual rooms--from the restoration period.

 

-INTERIOR FEATURES AND FINISHES-

Recommend
Identifying, retaining, and preserving interior features and finishes from the restoration period. These include columns, cornices, baseboards, fireplaces and mantels, panelling, light fixtures, hardware, and flooring; and wallpaper, plaster, paint, and finishes such as stencilling, marbling, and graining; and other decorative materials that accent interior features and provide color, texture, and patterning to walls, floors, and ceilings.

photo of a modest iron stairway from the restoration period that is significant to the interior of the building and would be preserved in work

Interior features are three-dimensional building elements or architectural details that are an integral part of the building as opposed to furniture. Retention of this modest iron stairway from the restoration period is crucial to preserving the significant interior of the building. Photo: NPS files

Not Recommended
Altering features or finishes from the restoration period.

Failing to properly document spaces, features, and finishes from the restoration period which may result in their loss.

Applying paint, plaster, or other finishes to surfaces unless the work can be substantiated historical documentation.

Stripping paint to bare wood rather than repairing or reapplying grained or marbled finishes from the restoration period to features such as doors and panelling.

Changing the type of finish or its color, such as painting a previously varnished wood feature, unless the work can be substantiated by historical documentation.

Protect and Maintain

Recommend
Protecting and maintaining masonry, wood, and architectural metals that comprise restoration period interior features through appropriate surface treatments such as cleaning, rust removal, limited paint removal, and reapplication of protective coating systems.

Protecting interior spaces, features and finishes against arson and vandalism before project work begins, erecting protective fencing, boarding-up windows, and installing fire alarm systems that are keyed to local protection agencies.

photo of a column base that combines real marble at the base and marbleized patterns on the plaster surface

Interior finishes from the restoration period often include patterned or inlaid designs in the wood flooring, decorative painting such as stenciling,
imitation marble or wood grain, wallpapering, tinwork, or tile floors. Shown here is a combination of real marble at the base of the column and marbleized patterns on the plaster surface of the column. Photo: NPS files.

Protecting interior features such as a staircase, mantel, or decorative finishes and wall coverings against damage during project work by covering them with heavy canvas or plastic sheets.Installing protective coverings in areas of heavy pedestrian traffic to protect historic features such as wall coverings, parquet flooring and panelling.

Removing damaged or deteriorated paints and finishes to the next sound layer using the gentlest method possible, then repainting or refinishing using compatible paint or other coating systems based on historical documentation.

Repainting with colors that are documented to the building's restoration period.

Limiting abrasive cleaning methods to certain industrial warehouse buildings where the interior masonry or plaster features do not have distinguishing design, detailing, tooling, or finishes; and where wood features are not finished, molded, beaded, or worked by hand. Abrasive cleaning should only be considered after other, gentler methods have been proven ineffective.

Evaluating the existing condition of materials to determine whether more than protection and maintenance are required, that is, if repairs to interior features and finishes will be necessary.

photo of ceilling being shored up from below during an interior restoration project

This ceiling is being shored up from below with toggle bolts to re-attach loose plaster prior to re-plastering and restoring significant finishes. Photo: NPS files.

Not Recommended
Failing to provide adequate protection to materials on a cyclical basis so that deterioration of interior features results.

Permitting entry into historic buildings through unsecured or broken windows and doors so that the interior features and finishes are damaged by exposure to weather or vandalism.

Stripping interiors of restoration period features such as woodwork, doors, windows, light fixtures, copper piping, radiators; or of decorative materials.

Failing to provide proper protection of interior features and finishes during work so that they are gouged, scratched, dented, or otherwise damaged.

Failing to take new use patterns into consideration so that interior features and finishes are damaged.

Using destructive methods such as propane or butane torches or sandblasting to remove paint or other coatings. These methods can irreversibly damage the historic materials that comprise interior features.

Using new paint colors that are inappropriate to the building's restoration period.

Changing the texture and patina of features from the restoration period through sandblasting or use of abrasive methods to remove paint, discoloration or plaster. This includes both exposed wood (including structural members) and masonry.

Failing to undertake adequate measures to assure the protection of interior features and finishes.

Repair

Recommend
Repairing interior features and finishes from the restoration period by reinforcing the historic materials. Repair will also generally include the limited replacement in kind--or with compatible substitute material--of those extensively deteriorated or missing parts of repeated features when there are surviving prototypes such as stairs, balustrades, wood panelling, columns; or decorative wall coverings or ornamental tin or plaster ceilings. The new work should be unobtrusively dated to guide future research and treatment.

paired photos showing the process of a paint investigation during Restoration

A complete paint investigation often needs to be conducted during Restoration. Paint samples are carefully collected onsite. (a) In the laboratory, an ultra violet light is used to identify pigment and binding media. Paint samples are then photographed. (b) Physical evidence documented through laboratory research provides a sound basis for an accurate restoration of painted finishes, such as the complex stencilling pictured here. Photo left: Courtesy, Andrea Gilmore; Photo right: Courtesy, Alexis Elza.

Not Recommended
Replacing an interior feature from the restoration period such as a staircase, panelled wall, parquet floor, or cornice; or finish such as a decorative wall covering or ceiling when repair of materials and limited replacement of such parts are appropriate.

Using a substitute material for the replacement part that does not convey the visual appearance of the surviving parts or portions of the interior feature or finish or that is physically or chemically incompatible.

Replace

Recommend
Replacing in kind an entire interior feature or finish from the restoration period that is too deteriorated to repair--if the overall form and detailing are still evident--using the physical evidence as a model for reproduction. Examples could include wainscoting, a tin ceiling, or interior stairs. If using the same kind of material is not technically or economically feasible, then a compatible substitute material may be considered. The new work should be unobtrusively dated to guide future research and treatment.

photo of ceiling medallion that was damaged and thus replaced during Restoration

Ceiling medallions may need replacement. In the case of this elliptical medallion from Rockland, Fairmont Park, Philadelphia, an impression was taken of the existing plaster, then new plaster elements were cast. Photo: David Flaharty.

 

Not Recommended
Removing a feature or finish from the restoration period that is unrepairable and not replacing it; or failing to document the new work.

The following Restoration work is highlighted to indicate that it involves the removal or alteration of existing historic interior spaces, features, and finishes that would be retained in Preservation and Rehabilitation treatments; and the replacement of missing interior spaces, features, and finishes from the restoration period using all new materials.

Removing Existing Features from Other Historic Periods

Recommend
Removing or altering interior spaces, features and finishes from other historic periods such as a later suspended ceiling or wood panelling.

Documenting materials and features dating from other periods prior to their alteration or removal. If possible, selected examples of these features or materials should be stored to facilitate future research.

Not Recommended
Failing to remove or alter an interior space, feature, or finish from another period, thus confusing the depiction of the building's significance.

Failing to document interior spaces, features, and finishes from other historic periods that are removed from the building so that a valuable portion of the historic record is lost.

Re-creating Missing Features from the Restoration Period

Recommend
Re-creating an interior space, or a missing feature or finish from the restoration period based on physical or documentary evidence; for example, duplicating a marbleized mantel or a staircase.

photo showing how missing composition ornament was re-created, based on documentary and physical evidence

Based on documentary and physical evidence, missing composition ornament was re-created within a larger restoration project. Photo: Jonathan Thornton.

Not Recommended
Constructing an interior space, feature, or finish that was part of the original design for the building but was never actually built; or constructing a feature which was thought to have existed during the restoration period, but for which there is insufficient documentation.

 

-GUIDELINES-

The Approach

Exterior Materials
Masonry
Wood
Architectural Metals

Exterior Features
Roofs
Windows
Entrances + Porches
Storefronts

Interior Features
Structural System Spaces/Features/Finishes
Mechanical Systems

Site

Setting

Special Requirements
Energy Efficiency
Accessibility
Health + Safety

The Standards

 

  HISTORICAL OVERVIEW - PRESERVING - REHABILITATING - restoring- RECONSTRUCTING

 main - credits - email

Historical Overview