Treatment of Historic Properties

The Secretary of the Interior's Standards for the treatment of historic properties are a series of concepts about maintaining, repairing, and replacing historic materials, as well as designing new additions or making alterations.

Four Approaches to the Treatment of Historic Properties

Standards and Guidelines provide a framework for decision-making about work or changes to a historic property. The Standards offer four distinct approaches to the treatment of historic properties:

  • Preservation places a high premium on the retention of all historic fabric through conservation, maintenance and repair. It reflects a building's continuum over time, through successive occupancies, and the respectful changes and alterations that are made.
  • Rehabilitation emphasizes the retention and repair of historic materials, but more latitude is provided for replacement because it is assumed the property is more deteriorated prior to work. (Both Preservation and Rehabilitation standards focus attention on the preservation of those materials, features, finishes, spaces, and spatial relationships that, together, give a property its historic character).
  • Restoration focuses on the retention of materials from the most significant time in a property's history, while permitting the removal of materials from other periods.
  • Reconstruction establishes limited opportunities to re-create a non-surviving site, landscape, building, structure, or object in all new materials.
    For more information, view Four Approaches to the Treatment of Historic Properties.

View Guidelines for Historic Buildings that offer general design and technical recommendations to assist in applying the Standards to a specific property.

Preservation Briefs

Preservation Briefs, which provide guidance on preserving, rehabilitating, and restoring historic buildings. These publications help historic building owners recognize and resolve common problems prior to work. To learn more, view Preservation Briefs.


View the preservation brief Architectural Character (PDF) that may help an owner or architect identify features or elements that give a building its visual and historic character.

Interpreting the Standards Bulletins

Interpreting the Standards Bulletins (ITS) assist building owners in applying the Standards to rehabilitation projects. The bulletins are case-specific and are provided as guidance only; they are not necessarily applicable beyond the unique facts and circumstances of each case. View ITS Bulletins to learn more.