User:Kbetsill/sandbox/The Conservation-Restoration of Historic Houses

An example of a conserved historic house. This is the Lyford House located at 376 Greenwood Beach Road, Tiburon, California.

The conservation-restoration of historic houses is the process of caring for and maintaining buildings of historic significance in order to preserve their materials and content. It covers the necessary measures that can be taken by conservators, curators, collections managers, and other museum professionals to conserve the material unique to a historic house. This practice includes understanding the composition and agents of deterioration of buildings and building materials, as well as the preventive conservation and interventive conservation measures that can be taken to increase their longevity. Houses were first thought of as historic rather than just old or interesting, during the early nineteenth century, and government protection of these historic houses was first given during the late nineteenth century. Historic homes are often eligible for special grant awards for preservation or conservation. What makes a historic home significant is often its architecture or its significance to the culture or history of the area, and there are some organizations that offer services to research the history of a home and others that provide repositories for users to document the history of their homes. Historic homes may still be inhabited, and thus should not be confused with historic house museums.

The Practice of Historic House Conservation-Restoration

Historic houses in many ways represent a region's or country's history, and is often the only representative of that community that the outside public sees. In conservation, the absolute maximum amount of the original material, in as unaltered a condition as possible, is preserved. Any repairs or additions must not remove, alter or permanently bond to any original material. All repairs or additions must be reversible and removable without affecting the condition of the original material now, and in the future . The conservation-restoration of historic houses follow these rules and focuses on preserving a building in a certain historic or period-era state.

A historic house needs to meet several criteria before being listed by a governing authority as "historic". It must be a certain age, usually at least 50 years old, and must be in the same state as it was when first declared historic in order to maintain its historic integrity. To be considered “historic”, a certain degree of historic significance must have happened there, like a significant event that occurred or an important person that had some sort of interaction there. The aim of the conservation-restoration of historic houses is to preserve the house in the state it once was when it first was considered historic. From the inside out, all paint, masonry, woodwork, furniture, and sculpture associated with the house at that point in time must be historically accurate and the structure integrity of the house must be able to protect and preserve the house for generations to come.

The Secretary of the Interior's Standards for Rehabilitation

When it comes to preserving historic houses, there are guidelines and standards that must be taken into account in order to meet federal laws. The major one in the case of historic structures is the Secretary of the Interior's Standards for Rehabilitation, which focuses on "historic buildings of all materials, construction types, sizes, and occupancy and encompass the exterior and the interior, related landscape features and the building's site and environment as well as attached, adjacent, or related new construction". This standard focuses on ten points of importance:

If a building qualifies to be listed under the National Register of Historic Places, it will have a similar plaque to the one shown above installed to distinguish it. This particular one is from the Orlando Phillips House, and has met all standards and guidelines to meet Federal laws and expectations.

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 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 archaeological 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.

It should be kept in mind that "the Standards are to be applied to specific rehabilitation projects in a reasonable manner, taking into consideration economic and technical feasibility". By following these guidelines, monitoring deteriorating agents, having a maintenance plan and treatment plan in place, and tracking risk management and preventative care issues, historic houses are able to be conserved, preserved, and treated well and professionally without risk of damaging or deteriorating the structure further.

Conservation Science

Historic houses are moved away from St. Luke's Medical Center in Boise, Idaho, during a hospital expansion. The H.C. Burnett House is at far right.

For historic house preservation, conservation science can involve analyzing wood type of the floors and walls, taking paint samples to test for color and see what chemicals make up the paint itself, and even revealing tool markings with stereo-microscopy when it comes to the structure of the house and seeing what type of tools were used in the building of the house. Historic house conservators are not only concerned with the structure of the house, but also the items housed inside the house. These items add significance to the structure and gives evidence to its importance, so it is equally important to the historic house as the physical house is. Conservation-science also important for these objects as well, like furniture, glassware, and artwork, to test their authenticity and help preserve them. The way these objects are housed within a historic house is also important. Making sure that the glass objects are stored away from acidic chemicals like formaldehyde, acetic, or formic acid and that cellulose-based materials such as paper and textiles are kept away from acid or alkaline hydrolysis is important for their preservation longevity.

Conservation-science can help reveal the minute details that the house holds that might not be easily recognized by the naked eye. It helps piece together the bigger story of the house and the stories of the people who lived there at one point. It also gives evidence of the date of the house, by the carbon dating of the wood of the floors and walls and the objects within the house, to help support its claim of being something worthy of being preserved. Conservation-science is the backbone of the preservation of historic houses.

Agents of Deterioration

Conservators work to preserve architectural features of The Holy Trinity Column in Olomouc, Czech Republic in 2006.

By keeping an eye on agents of deterioration, conservators help prevent a historic house from becoming damaged and preserve it better for future generations to enjoy. Historic house conservators have a lot to consider regarding preventative conservation and the agents of deterioration. By understanding the ten primary threats to heritage objects and how to detect, block, report, and treat the damage they cause, objects of historic importance are better preserved and increase their longevity. Pests can infest the wooden walls and floors of a historic house, especially mice, termites, carpentry ants and bees. They can weaken the structure and cause a lot of structural damage. They can also infest the furniture and the fabrics of the carpets and textiles in the house, causing deterioration to the smaller aspects of the house that gives evidence to its history. It is important to have a pest management plan in place, such as no food in the house and the proper extermination and disposal of pests, to prevent an infestation and protect the house. Theft is another agent, as historic houses have exterior elements that can be removed, such as stones from a garden wall, exterior house bricks, and even mailboxes. Inside the house, there are some smaller elements like glassware and household items that can "grow legs" if not secured properly. It's important for a historic house to have security procedures in place, like plexi-glass vitrines inside the house secured with security screws, security staff patrolling the inside and outside of the house, and maybe even a gate, fence, or a type of barrier on the exterior of the house to help secure the outside features.

Physical forces, such as natural elements like high winds, falling trees, and even improper supports built to help stabilize the house can play a role in the deterioration of a historic house. Making sure there are no dead or dying trees around the house that can fall and cause damage is a risk management issue that conservators will monitor closely, as well as making sure to monitor the structural needs of the house, such as putting in correct and safe supports for a wall if it is in risk of collapse, or stabilizing a roof to prevent leaks or collapse. For pollutants, keeping the inside of a historic house clean is important. Dust, atmospheric gas from the outside, and even human body oil touching an object can all cause damage to the collection. Pollutants such as “acetic acid, formic acid and formaldehyde tend to be the most common and damaging, causing corrosion of metals and calcareous materials, and sometimes attacking pigments, paper and textiles”, so it is important to have an air flow inside the house to keep the air fresh and free of pollutants . Regular cleaning of the carpets, cases, and heavily trafficked areas, and making sure there are proper barriers in place to prevent visitors from touching or accidentally bumping into delicate areas of the house or collections are important factors that conservators monitor.

As the Guidelines on Pollution Control in Museum Buildings state, “deterioration is usually slow and progressive: prolonged exposure can cause severe damage to a wide range of objects”. Monitoring light exposure, incorrect temperature and relative humidity, exposure to pests and pollutants, or any kind of physical forces are common tasks conservators undertake within a historic house. Relative humidly is a tricky aspect of preservation as the “control of room humidity to a lower limit of 40%RH… may be good for artifacts, [but it] is a potential source of damage to buildings exposed to cold winters”. The regular review of the humidity and temperature levels is a frequent occurrence and making sure that it is controlled by a reliable system is important. An outbreak of fire and a flooding incident are huge concerns at any museum, and historic houses are no different. There should be a reliable fire emergency alarm system throughout the house that includes loud noises, flashing lights, and sends an emergency alert to the nearest fire response station, so all can be aware of a potential emergency or fire. Conservators will make sure that fire doors are placed throughout the rooms of the house that can close when the alarm sound as to prevent the spread of fire. A flooding incident is a concern for any historic building, so conservators will have an accessible emergency response kit ready to go on site, complete with absorbent towels and cloths, gloves, and flashlights. Mops, buckets, and yellow caution signs will also be on hand to combat a flooding or leakage event.

Maintenance of Historic Houses

This historic house, known as Baldwins Hill, is in the midst of house restoration. This building had been painted white but it has been removed to reveal the interesting brickwork detail that is original to the house.

Keeping a certified historic house in the state that is accurate to it's past experiences in order to keep it's historic integrity is no easy task. It involves a lot of upkeep, preventive care, and risk management. The type of maintenance the house receives depends on the building materials and architectural features the house possesses. Organizing related work into a written set of procedures, or a Maintenance Plan, helps eliminate confusion, makes it easier to coordinate work effort, and creates a system for prioritizing maintenance tasks that takes into account the most vulnerable and character-defining elements of the house.

The first steps of maintenance is concerned with the structural integrity of the building. Conservators inspect what needs to be repaired, replaced, and any damages due to pests, water, or other damaging factors are first up to make sure the area is safe to work in. Then comes the planning to see the specifics of what exactly needs to be done and the budget the team has to work with. Does it need exterior waterproofing or the repair of window glass? Does it need to be re-roofed or the outside porch needs to be completely redone for safety reasons? These are questions conservators keep in mind while reviewing the structure. Conservators will then process and monitor work permits to be in accordance of state and federal building code and laws to help with the progress of preservation. In some cases, conservators will hire an architectural specialist to determine what style the house was built in and what masonry, wood, stucco, and building techniques were used, if the range of the structure's features are not within the expertise of the conservator. These details are important for the small features of the house, to hone into what is original to the house and what was an addition or replaced overtime . The architect’s report will form the foundation of a conservation treatment for the house going forward, including both the interior and exterior of the house, the building materials to be used in repairs, and even the type and color of the paint and wallpaper to be used to match the historic original materials. After analyzing the architect’s report, more details about the building is revealed and the treatment of the issues identified within the report are addressed. Maintenance is the most important preservation treatment for extending the life of a historic property and is also the most cost effective. Understanding the construction techniques of the original builders and the performance qualities of older building materials, using traditional maintenance and repair methods, and selecting in-kind materials where replacements are needed will help preserve both the physical building and its historic character.

Treatment of Historic Houses

This is the stage that addresses the needs of a historic house in order to be better preserved. This includes six different elements to properly treat the issues and risks a house faces:

An example of the treatment of an object. In this picture, a conservator is washing, removing degraded coatings, repatinating the bronze where abraded, and waxing a section of the Amateis doors.

1. A condition assessment to examine why an object is deteriorating,

2. A treatment plan or proposal to recommend in writing what should be done to preserve the object better and remedy existing damage,

3. Documenting the object before treatment with photography and an analytic report,

4. The physical treatment of the object by stabilizing, repairing, and restoring,

5. The after treatment documentation with photography and a written report detailing what exactly was done and what materials were used, and

6. Recommendations on the future care of the item.

The treatment process is especially important to the field of conservation-restoration as it directs how one must care for objects of historical importance and is also what people assume is the main aspect of museum conservation.

Treatment and the way to go about the treatment process depends on the type of object, collection, or structure that needs attention. A natural history collection would have a different treatment process than a technology and science-based collection, and that in turn would be a different process from treating a historic house. Because of this, there is a careful decision-making process that goes along with the treatment. Unfortunately, "conservation decisions are made about different situations that are unique and which have very little certain or verifiable data" . The choices made about the treatment of historic houses structure-wise are no different: they take time and careful evaluation. According to the National Park Service, “the choice of treatment depends on a variety of factors, including the property's historical significance, physical condition, proposed use, and intended interpretation" .

For historic buildings, there are four treatment options: preservation, rehabilitation, restoration, and reconstruction . The preservation aspect is concerned with the maintenance and repair of the existing historic materials and the retention of the building's original form. Rehabilitation is the acknowledgment of the possible need to alter or add to historic property to meet changing building uses while still retaining the buildings historic character. Restoration is the act of returning the building to its original period in time, depicting it in its original form, while removing evidence of other periods. Reconstruction is the more invasive treatment option and aims to recreate a part of the property that no longer exists, like rebuilding a garden shed that only has the foundation remaining . This option is used only if needed for interpretive purposes.

Restoration is the aspect that is concentrated on for historic houses, as "the purpose of restoration is to repair damage that has already occurred” . Identifying materials or features that are important to the historic structure to maintain its integrity is imperative and then "protecting and maintaining them are addressed. Protection generally involves the least degree of intervention and is preparatory to other work. Protection includes the maintenance of historic materials and features as well as ensuring that the property is protected before and during preservation work" . This phase of treatment might require an outside expert, like an architect, to evaluate the structure and draw up a detailed report on their findings to guide the treatment process.

See Also

Conservation-Restoration of Metals

Conservation and Restoration of Historic Gardens

Architectural Conservation

Conservation and Restoration of Cultural Heritage

Historic House Museums

External Links

The National Register of Historic Places

The Association for Preservation Technology International

Standards and Guidelines for Rehabilitating Historic Buildings

References

Category:Conservation and restoration of cultural heritage Category:Historic preservation Category:Historic houses