Preservation is the process of maintaining and protecting the existing form, materials, and integrity of a historic property. It focuses on repair and upkeep rather than replacement or new construction. New additions are excluded, but limited, sensitive system upgrades for functionality are allowed.

1. Use the property as it was historically or adapt it with minimal change; stabilize if no use is identified.

2. Preserve historic character; avoid replacing or altering intact features and spaces.

3. Stabilization and conservation must be compatible, identifiable upon inspection, and well documented.

4. Retain changes that have gained historic significance.

5. Preserve distinctive materials, features, and craftsmanship.

6. Evaluate historic features to determine needed repair; limited replacements must match original materials and appearance.

7. Use the gentlest treatments; avoid those that damage historic materials.

8. Protect archaeological resources; mitigate if disturbance is necessary

Rehabilitation is the process of enabling a compatible use of a property through repairs, changes, and additions while preserving its historic, cultural, or architectural values.

1. Use the property as it was historically or adapt it with minimal changes to key historic features.

2. Preserve the property's historic character; avoid removing or altering distinctive elements.

3. Do not add features that create a false historical appearance.

4. Retain and preserve later additions that have become historically significant.

5. Preserve distinctive materials, features, and craftsmanship.

6. Repair deteriorated features when possible; replacements must match the original and be evidence-based.

7. Use the gentlest treatments; avoid those that harm historic materials.

8. Protect archaeological resources; mitigate if disturbance is needed.

9. New work (additions or changes) must not harm historic elements and should be clearly distinguishable yet compatible.

10. New construction should be reversible, preserving the original form and integrity.

Restoration is the process of accurately showing a property’s appearance at a specific time by removing features from other periods and reconstructing missing elements from the restoration period. Limited, careful updates to mechanics and code-required work are allowed in order to keep the property functional.

1. Use the project as it was historically or for a new use that reflects its restoration period.

2. Retain and preserve materials and features from the restoration period; avoid altering key spaces or features.

3. Stabilize and conserve restoration-period materials with compatible, documented work identifiable on close inspection.

4. Document features from other periods before altering or removing them.

5. Preserve distinctive materials, finishes, and craftsmanship from the restoration period.

6. Repair rather than replace deteriorated features; replacements must match original design and materials.

7. Replace missing features only with solid evidence; avoid adding conjectural or unrelated elements.

8. Use the gentlest chemical/physical treatments; avoid damage to historic materials.

9. Protect archaeological resources; mitigate if disturbance is necessary.

10. Do not construct designs never historically executed.

Reconstruction is the process of using new construction to replicate the appearance of a lost site, structure, or object at a specific historic time and place.

1. Reconstruction is used to recreate lost parts of a property when accurate evidence exists and it’s vital for public understanding.

2. Investigation must precede reconstruction to identify key features; mitigation is required if disturbed.

3. Remaining historic materials and spatial relationships should be preserved.

4. Reconstruction must accurately replicate historic features based on evidence, not guesswork or unrelated designs.

5. Reconstructions must be clearly marked as modern recreations.

6. Designs not historically executed should not be built.