3-17-105. STANDARDS FOR REHABILITATION AND DESIGN GUIDELINES.
The following standards and guidelines shall be used by the Historic Preservation Commission in determining the historic appropriateness of any application pertaining to Historic Landmark properties. This includes individually designated Landmark properties and both contributing and noncontributing properties in Landmark-designated historic districts. In approving an application for a Certificate of Appropriateness, the Historic Preservation Commission shall find that the project substantially complies with all of the following standards and guidelines that pertain to the application and that the decision is in the best interest of the City.
(1) Standards for Rehabilitation. These standards are based on the “Secretary of the Interior’s Standards for Rehabilitation,” which serve as a national and state model for appropriate preservation treatment. The standards are as follows:
a. A property shall be used for its historic purpose or be placed in a new use that requires minimal change to the defining characteristics of the building and its site and environment.
b. The historic character of a property shall be retained and preserved. The removal of historic materials or alteration of features and spaces that characterize a property shall be avoided.
c. Each property shall be recognized as a physical record of its time, place, and use. Changes that create a false sense of historical development, such as adding conjectural features or architectural elements from other buildings, shall not be undertaken.
d. Most properties change over time; those changes that have acquired historic significance in their own right shall be retained and preserved.
e. Distinctive features, finishes, and construction techniques or examples of craftsmanship that characterize a property shall be preserved.
f. Deteriorated historic features shall be repaired rather than replaced. Where the severity of deterioration requires replacement of a distinctive feature, the new feature shall match the old in design, color, texture, and other visual qualities and, where possible, materials. Replacement of missing features shall be substantiated by documentary, physical, or pictorial evidence.
g. Chemical or physical treatments, such as sandblasting, that cause damage to historic materials shall not be used. The surface cleaning of structures, if appropriate, shall be undertaken using the gentlest means possible.
h. Significant archeological resources affected by a project shall be protected and preserved. If such resources must be disturbed, mitigation measures shall be undertaken.
i. New additions, exterior alterations, or related new construction shall not destroy historic materials that characterize the property. The new work shall be differentiated from the old and shall be compatible with the massing, size, scale, and architectural features to protect the historic integrity of the property and its environment.
j. New additions and adjacent or related new construction shall be undertaken in such a manner that if removed in the future, the essential form and integrity of the historic property and its environment would be unimpaired.
(2) General Design Guidelines.
a. Landmark Buildings and Contributing Buildings in Landmark-designated Historic Districts.
i. Avoid demolition of landmark and contributing buildings. They are a finite resource and cannot be replaced.
ii. Vacant buildings should be weather- and vandal-proofed in order to minimize further deterioration and the threat to public safety.
iii. Rehabilitation work, especially on the exterior and the principal facade, should preserve existing historic features or replace them if absolutely necessary with features and materials known to have existed on the building. Avoid “dressing up” buildings by adding features based on speculation.
iv. Avoid moving buildings whenever possible, especially to create artificial groupings of historic buildings. If buildings must be moved, the new site should be similar to the original site, and the original setback and orientation of the building on the lot should be replicated.
b. Additions to Landmark and Contributing Buildings and Construction of New Buildings within an Historic District.
i. New additions to landmark and contributing buildings should be subordinate to the original building, that is, lower in height, attached to the rear or set back along the side, and subordinate in scale and architectural detailing.
ii. Height, width, setback, roof shape, and the overall scale and massing of new buildings should be compatible with surrounding historic buildings and the overall streetscape.
iii. Materials on at least the primary facade(s) should be similar to original materials on facades of surrounding historic buildings (usually brick, stucco, stone, or wood siding, depending on the specific characteristics of the district.
iv. Architectural details (including wood or metal trim, porches, cornices, arches, window and door features, etc.) should not replicate historic features on surrounding historic buildings.
v. Window and door openings should be similar in size and orientation (vertical or horizontal) to openings on historic buildings and should take up about the same percentage of the overall facade as those on surrounding historic buildings.
vi. Proportion of Principal Facades. The relationship of the width to the height of the principal elevations shall be in scale with surrounding structures and streetscape. Wider new buildings can be divided into segments that more closely resemble the facade widths of historic buildings.
vii. Roof Shape. The roof shape of a building shall be visually compatible with the surrounding structures and streetscape. Unusual roof shapes, pitches, and colors are discouraged.