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Caring for your Historic Building

Tips for preserving historic structures.

What You Can Do
Glossary of Helpful Terms
Preserve, Rehabilitate, Restore or Reconstruct?
The Two “Golden Rules” or Do the Right Thing
Ten Basic Principles for Sensitive Rehabilitation
Standards for Rehabilitation from the U.S. Secretary of the Interior
Window Repair or Replacement?
Painting Your Historic Home

What You Can Do

  • Understand the architectural history and evolution of your building before starting a work project. Consult a local historical society and the Clackamas Historical Review Board to find documents that can assist your research, such as drawings and records pertaining to your house and its neighborhood.
  • "Repair rather than replace" historic materials, such as masonry, wood and architectural metals that comprise a building's features and character. Remember that historic preservation is based, in part, on the retention of historic building materials.
  • Maintain your historic building regularly. For example, clean gutters several times a year and keep painted wood surfaces in good repair through scraping, sanding, priming and repainting, as needed.
  • Improve energy efficiency. Install storm windows that are compatible with the character of the historic windows rather than replacing windows with new ones.
  • Join a local preservation organization so that you have a voice in preservation.

Glossary of Helpful Terms

  • Preserve: To maintain a structure’s existing form through careful maintenance and repair.
  • Reconstruct: To re-create an historic building that has been damaged or destroyed; to erect a new structure resembling the old using historical, archaeological and/or architectural documents.
  • Rehabilitate: To repair a structure and make it usable again while preserving those portions or features of the property that are historically and culturally significant. For example, rehabilitation might include an updated kitchen while retaining the historic stairwell and fireplaces. Most common approach for private houses.
  • Remodel: To change a building without regard to its distinctive features or style. Often involves changing the appearance of a structure by removing or covering original details and substituting new materials and forms.
  • Renovate: To repair a structure and make it usable again without attempting to restore its historic appearance or duplicate original construction methods or material.
  • Restore: To return a building to its form and condition as represented by a specified period of time using materials that are as similar as possible to the original materials.
  • Stabilize: To protect a building from deterioration by making it structurally secure, while maintaining its current form.

Preserve, Rehabilitate, Restore or Reconstruct?

"Before any historic preservation project is begun, a number of fundamental decisions need to be made. How will the property be used? Will the property be restored to its original condition or rehabilitated for contemporary use? How can the significant architectural and historical features of the building be preserved? What steps need to be taken?  Although 'rehabilitation' and 'restoration' might sound alike, the end result is quite different".  (From Downtown Moultrie Design B Guidelines, Moultrie Georgia, Moultrie-Colquitt Historic Preservation Commission).

Without question, rehabilitation, the only approach that includes alterations and additions for a contemporary use, is most frequently applied to commercial and residential buildings in historic districts. Having said that, here is an important question:

Is it all rehab? The answer is "no". If a historic building will be preserved, restored or reconstructed, you want to be sure your work fits time and place by applying the most appropriate set of standards, not simply using the Standards for Rehabilitation as a "catch-all". Each of the four treatments has a different relationship to the historical timeline and a different scope of work.

For example, if you want to stabilize and preserve a historic building to keep it the way it looks now, use the Standards for Preservation.

  • Use the property as it was used historically or find a new use that maximizes retention of distinctive features.
  • Preserve the historic character (with changes over time).
  • Stabilize, consolidate and conserve existing historic materials.
  • Replace minimum amount of fabric necessary and in kind (matching materials).

If you want to update a building for a continuing or new use through repair, alterations and additions, use the Standards for Rehabilitation.

  • Use the property as it was used historically or find a new use that requires minimal change to distinctive features.
  • Preserve the historic character (with its changes over time).
  • Do not make changes that falsify the history of the property.
  • Repair deteriorated historic materials and features. Replace severely deteriorated or missing features using the same material or visually compatible material.
  • Do not destroy distinctive materials and features when constructing a new addition or making alterations. New work should be compatible with the old. But do not try to imitate it. Work should also be reversible, that is, it could be removed in the future if necessary.

If you want to backdate it consistently to an earlier period by removing later features, use the Standards for Restoration.  

  • Remove features from other periods, but document them first.
  • Stabilize, consolidate and conserve features from the restoration period.
  • Replace a severely deteriorated feature from the restoration period with a matching feature (limited substitute materials may be used).
  • Replace missing features from the restoration period based only on pictorial documentation and physical evidence. Do not make changes that mix periods to create a "hybrid" building that never existed historically.

If you want to re-establish a historic building in time that has vanished, use Standards for Reconstruction.  

  • Do not reconstruct vanished portions of a property unless the reconstruction is essential to the public understanding.
  • Reconstruct to one period of significance based on documentary and physical evidence.
  • Precede reconstruction with thorough archeological investigation.
  • Preserve any remaining historic features.
  • Re-create the appearance of the property (substitute materials may be used).
  • Identify the reconstructed property as a contemporary re-creation.
  • Do not execute a design that was never built.

The Two “Golden Rules” or Do the Right Thing

1. Thou Shalt Not Destroy Good Old Work

Interpretation: You can alter or tear down anything you have built yourself, but you should approach with caution and respect the good work on which someone else lavished time, money and energy. It is part of our common heritage.

A building is a collection of individual details. Every time you replace a detail, it changes the character of the building. It is better to repair, rather than replace, original elements and material whenever possible. When replacement is called for, the replacement should resemble the original as closely as practical with respect to proportion, texture and material.

After a series of seemingly minor replacements, significant changes in the building's appearance can result. Ironically, these alterations rob the building of the antique character that attracted the buyer to it in the first place. In addition, modern replacements often are not of the same quality materials and workmanship as the older element. Value judgments are involved when deciding what constitutes good old work. In general, work can be called "good" if it meets these three criteria:

  1. It is fabricated from good quality materials;
  2. The workmanship is good;
  3. The design typifies a particular style or works in harmony with the rest of the structure.

These criteria for judging good old work can also apply to accretion that is not original to the house. In general, it is best to leave these additions if;

  1. They pass the test for good work; and
  2. They don't interfere with the operation of the structure as you intend to use it.

2. To Thine Own Style Be True

Interpretation: Your house (or building) represents a specific architectural style. Learn everything you can about that particular style and then let your rehabilitation or restoration bring out the character and flavor of that style.
Every house or commercial building had an original design concept. This is true whether it was designed by a famous architect or constructed by an anonymous carpenter-builder. Your work should enhance and clarify this original design concept. Or, at the very least, it should not detract from it.
Source: Old House Journal New Compendium 1983

Ten Basic Principles for Sensitive Rehabilitation

“What Every Restorer Should Know,” an article by Susan Morse, appeared in the January/February 1989 issue of Historic Preservation.  Morse lists the Department of the Interior’s “Ten Basic Principles for Sensitive Rehabilitation,” also known as the “Do’s and Don’t’s for First-Timers and Veterans.”

  1. Make every effort to use the building for its original purpose.
  2. Do not destroy distinctive original features.
  3. Recognize all buildings as products of their own time.
  4. Recognize and respect changes that have taken place over time.
  5. Treat sensitively distinctive stylistic features or examples of skilled craft work.
  6. Repair rather than replace worn architectural features when possible. When replacement is necessary, new material should match the old in design, composition and color.
  7. Clean facades using the gentlest methods possible. Avoid sandblasting and other damaging methods.
  8. Protect and preserve affected archeological resources.
  9. Compatible contemporary alterations are acceptable if they do not destroy significant historical or architectural fabric.
  10. Build new additions so they can be removed without impairing the underlying structure.

Standards for Rehabilitation from the U.S. Secretary of the Interior

The Secretary of the Interior’s Standards for Rehabilitation are used for properties owned by the National Park Service and for regulation of National Register properties.  When used as guidelines by historic property owners, these standards make good aesthetic and economic sense when rehabilitating any historic structure.  For more info visit:

  1. 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.
  2. 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.
  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 architectural elements from other buildings, shall not be undertaken.
  4. Most properties change over time; those changes that have acquired historic significance in their own right shall be retained and preserved.
  5. Distinctive features, finishes and construction techniques or examples of craftsmanship that characterize a historic property shall be preserved.
  6. 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.
  7. 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.
  8. Significant archeological resources affected by a project shall be protected and preserved. 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 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.
  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.

Window Repair or Replacement?

During rehabilitation of historic buildings, the question of how to treat the windows is inevitably raised. The window styles, materials and arrangement (or fenestration) together are one of the most distinctive architectural features of a building and, too often, one of the first things replaced with historically inappropriate and unsustainable vinyl windows. Proceed with utmost caution in your long-range window care!  Think repair rather than replace and realize that thoughtfully caring for old houses requires compromises.

Historic wood windows are often made of old-growth timber, an irreplaceable resource; retaining them is environmental sustainability.  Caulked and well maintained, their “R” factor is nearly indistinguishable from new “weatherized” windows.  Repairing and rebuilding historic wood windows is economical sustainability, spending dollars locally rather than purchasing newly fabricated windows made of energy-consumptive materials, distantly manufactured and transported with fossil fuels.  Preserving the unique, local character of the building is cultural sustainability.

Within the decision-making process for deciding to replace or renovate an existing window, energy consideration should not be the primary criteria, but should not be ignored. The desire to retain the historic character of the windows, and the actual historic material of which the windows are made, is seen as competing with the desire to improve energy performance and decrease long-term window maintenance costs. Replacement of window sash, the use of windows inserted inside existing jambs or whole window replacement is often advocated in the name of energy efficiency, long-term maintenance, cost reduction, ease of operation and better assurance of window longevity.

Other approaches to improve the energy efficiency of historic windows retain all or part of the existing sash and balance system, and typically include interior or exterior storm window rehabilitation or replacement. Some building renovations only include storm window repair or replacement and prime window maintenance.

The US Department of the Interior and the National Park Service did a study to test the assumption that historic windows can be retained and upgraded to approach the thermal efficiency of replacement sash or window inserts. This study investigated the types of historic windows and viable methods for striking the balance between retaining a window’s historic character and energy efficiency 
The findings of the study indicated the wide range of window upgrade options and installed costs resulted in annual heating cost savings that were similar. Within several types of window upgrades tested, there were examples where inappropriate application of an upgrade or an incomplete installation resulted in below average energy performance. However, when installed carefully, virtually all the options studied produced savings in a similar range.

Once the decision to upgrade or replace an existing window is made, it is important to select a strategy that not only meets the needs of the building occupants and owners but also utilizes techniques that achieve the highest levels of energy savings and occupant comfort. In general:

  • Window upgrades using existing sash can achieve performance indistinguishable from replacement sash, but economics of the upgrade depend on the leakiness of the original window.
  • If the existing window is loose, it can often be cost-effective to address this leakage, including air leakage between the window and rough opening as well as between an exterior storm window and trim. If the window is already in typical or tight condition, an upgrade is unlikely to be cost-effective regardless of the cost-benefit test used.
  • If the windows have single glass, it is worthwhile considering installing a second layer, including the options of storm windows, replacement insulated glass units, energy panel and use of low emissivity gas (low-E).

The advantages of renovating existing windows versus replacements in an historic building include saving the historic value and design of the window as well as the interior/exterior appearance. For these reasons, it is advantageous to investigate methods of rehabilitation in an historic building. It has been shown that effective window rehabilitation can be accomplished at a lower cost than replacement windows while still resulting in significant energy savings.

For more information concerning windows, see the September/October 1994 issue of TRADITIONAL BUILDING. To get a copy of the complete study condensed above, contact the Department of the Interior NPs National Center for Preservation Technology and Training and request Publication No. 1996-08. Another report can be found in Publication No. 1997-17. Get NCPTT publications on the website at

Painting Your Historic Home

There are several publications available for preservationists interested in paint colors. The National Trust’s Preservation Books carries Paint in America: The Colors of Historic Buildings, by Roger Moss. For price and ordering information, visit the Preservation Books website at Mr. Moss has also written several other books concerning historic paint colors which are available at bookstores and libraries or through websites. The National Park Service’s Preservation Briefs will also be helpful and can be accessed at: Two briefs which are particularly useful are: No.10 - Exterior Paint Problems on Historic Woodwork and No. 28 - Painting Historic Interiors.

The National Trust has worked extensively with the Valspar Corporation to develop an exclusive collection of historical colors. The resulting American Tradition® palette, sold at Lowe's Home Improvement Warehouses, covers the spectrum of historic hues. It features 250 colors certified by the National Trust, having been developed from samples taken from the Trust's Historic Sites. These 100% acrylic paints are available for both interior and exterior work and all carry a lifetime warranty. To see the possibilities visit: Valspar donates a portion of every paint sale to the National Trust and supplies paint to the National Trust’s Historic Sites.

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