Secretary of the Interior's Standards
Preservation:
The act or process of applying measures necessary to sustain the existing form, integrity and materials of an historic property.
Restoration:
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.
Rehabilitation:
The act or process of making possible a compatible use for a property through repair, alterations and additions while preserving those portions or features that convey its historical, cultural or architectural values.
Reconstruction:
The act or process of depicting, by means of new construction, the form, features and detailing of a non-surviving site, landscape, building, structure or object for the purpose of replicating its appearance at a specific period of time and in its historic location.