Every reasonable effort shall be made to provide a compatible use for property that requires minimal alteration of the building, structure or site and its environment, or to use a property for its originally intended purpose.

The distinguishing original qualities or character of a building, structure, or site and its environment shall not be destroyed. The removal or alteration of any historic material or distinctive architectural features should be avoided when possible.

All buildings, structures and sites shall be recognized as products of their own time. Alterations that have no historical bases and that seek to create an earlier appearance shall be discouraged.

Changes that may have taken place in the course of time are evidence of the history and development of a building, structure, or site and its environment. These changes may have acquired significance in their own right, and this significance shall be recognized and considered.

Distinctive stylistic features or examples of skilled craftsmanship that characterize a building, structure or site shall be treated with sensitivity.

Deteriorated architectural features shall be repaired rather than replaced, whenever possible. In the event replacement is necessary, the new material should match the material being replaced in composition, design, texture, and other visual qualities. Repair or replacement of missing architectural features should be based on accurate duplication of features, substantiated by historic, physical, or pictorial evidence, rather than on conjectural design or the availability of different architectural elements from other buildings or structures.

The surface cleaning of structures shall be undertaken with the gentlest means possible. Sandblasting and other cleaning methods that will damage the historic building materials shall be avoided.

Contemporary design for alterations and additions to existing properties shall not be discouraged when such alterations and additions do not destroy significant historical, architectural, or cultural material, and such design is compatible with the size, scale, color, material, and character of the property, neighborhood, or environment.