Eager to learn about how you can get your hands dirty (literally) in preservation work? Then you’re in luck, because today’s toolkit elaborates on the Secretary of the Interior’s Standards for the Treatment of Historic Properties -- the criteria about the physical approach to fixing up and maintaining historic places.

The Secretary of the Department of the Interior has a series of Standards to abide by regarding the maintenance, replacement, and repairing of historic materials, as well as the design of new additions and alterations to a property.

In addition, there are also Guidelines that recommend how the Standards can be applied to a specific property when it comes to design and technical treatment. Together, they serve as a frame of reference in the decision-making process about the changes to a historic property.

These Standards and Guidelines cover historic properties of all types, materials, sizes, construction styles, and uses (both interior and exterior). They can be applied to a property’s landscape features, environment, site, or other related new construction as well.

There are four specific, but interrelated approaches to the treatment of historic properties: preservation, rehabilitation, restoration, and reconstruction. Each has its own set of Standards and Guidelines, which you can find here.

Because each technique has about six to ten Standards apiece (and many of them are common sense historic preservation principles), this toolkit explains the significance of each technique and how it can be applied to a historic property.

Preservation as a treatment focuses on the maintenance and repair of existing historic materials and retaining the form and character of a property as it has evolved over time. Consider preservation when:

• The property’s distinct materials, features, and spaces are mostly intact and convey historic significance without needing extensive repair or replacement.
• The depiction of the historic property at a particular period of time is not appropriate.
• A continuing or new use of the historic property doesn't need additions or extensive alterations.

Rehabilitation as a treatment recognizes the need to alter or add to a historic property in order to meet continuing or changing uses while simultaneously retaining the character of the historic property. Consider rehabilitation when:

• The repair and replacement of deteriorated features is necessary.
• Alterations or additions to the property are planned for a new or continued use of the property.
• The depiction of the historic property at a particular period of time is not appropriate.

Restoration as a treatment focuses on depicting a property at a certain period of time in history, and removes evidence from other periods that aren't appropriate. Consider restoration when:

• The property’s design, architectural, or historical significance during a particular time outweighs the potential loss of extant materials, features, spaces, and finishes that characterize other historical periods.
• There is substantial physical and documentary evidence for the restoration work.
• Contemporary alterations or additions are not planned.

Reconstruction as a treatment sets out to re-create lost or non-surviving aspects or portions of a property for interpretive purposes. Consider reconstruction when:

• A contemporary depiction is necessary in order to understand and interpret a property’s historic value.
• No other property with the same associative value has survived.
• Sufficient historical documentation exists to ensure an accurate reproduction of the property.

Again, these treatments are not the Standards and Guidelines themselves. Rather, think of the four treatments like different types of medicine for a historic property that’s feeling under the weather -- and the Standards and Guidelines are the directions.