At the bottom of this page you will find a pdf copy of the current Mount Vernon Iowa Design Guideline Booklet – Preservation and Rehabilitation Dos and Don’ts for Commercial and Residential Structures.
The following content is the most recent addendum to the Design Guideline Booklet. The guidance in the addendum supersedes any offered in the Booklet.
Guide for Renovation, Additions, and New Construction
Rules of Thumb for Rehabilitating a Historic Building
The Design Guidelines for Mount Vernon Historic Districts are based on the Secretary of the Interior’s Standards for Historic Rehabilitation. The following, drawn from the Secretary of the Interior’s Standards for Rehabilitation, should be kept in mind when altering a property in the local historic districts. For more information, see https://www.nps.gov/tps/standards.htm
1. When adapting a property to a new use, distinctive materials, features, spaces, and spatial relationships shall be maintained.
2. The historic character of a property shall be retained and preserved. The removal of distinctive materials or alteration of features, spaces and spatial relationships that characterize a property shall be avoided.
3. 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 elements from other historic properties, shall not be undertaken.
4. Changes to a property that have acquired historic significance in their own right shall be retained and preserved.
5. Distinctive materials, features, finishes, and construction techniques or examples of craftsmanship that characterize a property shall be preserved.
6. Deteriorated historic features 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 will be substantiated by documentary and physical evidence, such as early photographs of the structure, when possible.
7. Chemical or physical treatments, if appropriate, shall be undertaken using the gentlest means possible. Treatments that cause damage to historic materials shall not be used. Professional advice is recommended before using these processes.
8. Archaeological resources shall be protected and preserved in place. If such resources must be disturbed, mitigation measures shall be undertaken.
9. New additions, exterior alterations, or related new construction shall not destroy historic materials, features, and spatial relationships that characterize the property. The new work shall be differentiated from the old and shall be compatible with the historic materials, features, size scale and proportion, and massing to protect the integrity of the property and its environment, including the relation to the surrounding properties.
10. 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.
Solar Panel Guidelines
According to the Technical Preservation Services branch of the National Park Service: “Solar panels installed on a historic property in a location that cannot be seen from the ground will generally meet the Secretary of the Interior’s Standards for Rehabilitation. Conversely, an installation that negatively impacts the historic character of a property will not meet the Standards.” To meet the spirit of this guideline, the Mount Vernon Historic Preservation Commission requires property owners to install solar panels with the lowest possible profile to minimize visibility from the street. On a sloped roof, panels must lie parallel to the roof surface, and on a flat roof, the panels should be sloped such that they are not visible from the street. The preferred locations for solar panels are: 1) on a detached outbuilding or on poles at a distance from historic structures, 2) on the back of the historic structure, or 3) on the side of the historic structure. The MVHPC will consider approving placement on the front roof of a historic structure if that is the only feasible location for the solar panels. The solar panels and support rack systems should be a solid black color with no visible grid.