- Standards—Treatment of Historic Properties
- Standards & Guidelines for Preservation
- Standards & Guidelines for Rehabilitation
- Standards & Guidelines for Reconstruction
- Other Guidelines for Applying the Standards
- History of the Standards
- Rehabilitation Standards—Tax Credit Projects
- Planning Successful Rehabilitation Projects
Restoration as a Treatment
Restoration is defined as the act or process of accurately depicting the form, features, and character of a property as it appeared at a particular period of time by means of the removal of features from other periods in its history and reconstruction of missing features from the restoration period. The limited and sensitive upgrading of mechanical, electrical, and plumbing systems and other code-required work to make properties functional is appropriate within a restoration project.
Standards for Restoration
- A property will be used as it was historically or be given a new use that interprets the property and its restoration period.
- Materials and features from the restoration period will be retained and preserved. The removal of materials or alteration of features, spaces and spatial relationships that characterize the period will not be undertaken.
- Each property will be recognized as a physical record of its time, place and use. Work needed to stabilize, consolidate and conserve materials and features from the restoration period will be physically and visually compatible, identifiable upon close inspection and properly documented for future research.
- Materials, features, spaces and finishes that characterize other historical periods will be documented prior to their alteration or removal.
- Distinctive materials, features, finishes and construction techniques or examples of craftsmanship that characterize the restoration period will be preserved.
- Deteriorated features from the restoration period will be repaired rather than replaced. Where the severity of deterioration requires replacement of a distinctive feature, the new feature will match the old in design, color, texture and, where possible, materials.
- Replacement of missing features from the restoration period will be substantiated by documentary and physical evidence. A false sense of history will not be created by adding conjectural features, features from other properties, or by combining features that never existed together historically.
- Chemical or physical treatments, if appropriate, will be undertaken using the gentlest means possible. Treatments that cause damage to historic materials will not be used.
- Archeological resources affected by a project will be protected and preserved in place. If such resources must be disturbed, mitigation measures will be undertaken.
- Designs that were never executed historically will not be constructed.
Choosing Restoration as a Treatment
Restoration is the treatment that should be followed when the expressed goal of the project is to make the building appear as it did at a particular—and at its most significant—time in its history. The guidance provided by the Standards for Restoration and Guidelines for Restoring Historic Buildings is to first identify the materials and features from the restoration period. After these materials and features have been identified, they should be maintained, protected, repaired, and replaced, when necessary. Unlike the other treatments in which most, if not all, of the historic elements are retained, restoration will likely include the removal of features from other periods. Missing features from the restoration period should be replaced, based on physical or historic documentation, with either the same or compatible substitute materials. Only those designs that can be documented as having been built should be recreated in a restoration project.
When the property’s design, architectural, or historical significance during a particular period of time outweighs the potential loss of extant materials, features, spaces, and finishes that characterize other historical periods; when there is substantial physical and documentary evidence for the work; and when contemporary alterations and additions are not planned, Restoration may be considered as a treatment. Prior to undertaking work, a particular period of time, i.e., the restoration period, should be selected and justified, and a documentation plan for Restoration developed.
The Guidelines for the Treatment of Historic Properties illustrate the practical application of the Standards for Restoration to historic properties.