Conservation and restoration of immovable cultural property describes the process through which the material, historical, and design integrity of any immovable cultural property are prolonged through carefully planned interventions. The individual engaged in this pursuit is known as an architectural conservator-restorer. Decisions of when and how to engage in an intervention are critical to the ultimate conservation-restoration of cultural heritage. Ultimately, the decision is value based: a combination of artistic, contextual, and informational values is normally considered. In some cases, a decision to not intervene may be the most appropriate choice.
The Conservation Architect must consider factors that deal with issues of prolonging the life and preserving the integrity of architectural character, such as form and style, and/or its constituent materials, such as stone, brick, glass, metal, and wood. In this sense, the term refers to the "professional use of a combination of science, art, craft, and technology as a preservation tool" [1] and is allied with – and often equated to – its parent fields, of historic environment conservation and art conservation.
In addition to the design and art/science definition described above, architectural conservation also refers to issues of identification, policy, regulation, and advocacy associated with the entirety of the cultural and built environment. This broader scope recognizes that society has mechanisms to identify and value historic cultural resources, create laws to protect these resources, and develop policies and management plans for interpretation, protection, and education. Typically this process operates as a specialized aspect of a society's planning system, and its practitioners are termed built or historic environment conservation professionals.
Architectural conservation is the process by which individuals or groups attempt to protect valued buildings from unwanted change. [2]
As a movement, architectural conservation in general, and the preservation of ancient structures specifically, gained momentum during the 18th and 19th centuries. It was a response to modernism and its corresponding architectural perspective, which eschewed sentimental attachment to old buildings and structures in favor of technological and architectural progress and change. Prior to this time most of the ancient buildings that were still standing had only survived because they either had significant cultural or religious import, or they had yet to be discovered. [3]
The growth of the architectural conservation movement took place at a time of significant archaeological discovery and scientific advancement. Those educated in the field began to see various examples of architecture as either being "correct" or "incorrect". [3] Because of this, two schools of thought began to emerge within the field of building conservation.
Preservation/Conservation were used interchangeably to refer to the architectural school of thought that either encouraged measures that would protect and maintain buildings in their current state, or would prevent further damage and deterioration to them. This school of thought saw the original design of old buildings as correct in and of themselves. Two of the main proponents of preservation and conservation in the 19th century were art critic John Ruskin and artist William Morris.
Restoration was the conservationist school of thought that believed historic buildings could be improved, and sometimes even completed, using current day materials, design, and techniques. In this way it is very similar to the Modernist architectural theory, except it does not advocate the destruction of ancient structures. One of the most ardent supporters of this school of thought in the 19th century was the French architect Eugène Viollet-le-Duc. Victorian restoration of medieval churches was widespread in England and elsewhere, with results that were deplored at the time by William Morris and are now widely regretted.
The Department of the Interior of the United States defined the following treatment approaches to architectural conservation:
Other nations recognize some or all of these as potential treatments for historic structures. Canada recognizes preservation, rehabilitation, and restoration. The Burra Charter, for Australia, identifies preservation, restoration, and reconstruction.
The earliest building materials used by ancient peoples, such as wood and mud, were organic. [5] Organic materials were used because they were plentiful and renewable. Unfortunately, the organic materials used were also very susceptible to the two most significant impediments to preservation and conservation: the elements and life (both human and animal). [5] Over time inorganic materials like brick, stone, metal, concrete, and terra cotta began to be used by ancient people instead of organic ones, due to their durability. [5] In fact, we know that these materials are durable because many ancient structures that are composed of them, even some built as far back as the Bronze Age, like Egypt's Great Pyramids, still stand today.
Ancient buildings such as the Egyptian pyramids, the Roman Colosseum, and the Parthenon face common preservation issues. The most prominent factors affecting these structures are the environment, pollution, and tourism.
As the Earth's climate patterns change, so too do the environmental conditions governing these buildings. For example, the Colosseum has already faced lightning, fire, and earthquakes. [6] The changing climate increases the accumulation of salt crystals on the outside of monuments like the Colosseum and the Parthenon. [7] This phenomenon increases the deterioration of these buildings.
The salt crystals further contribute to the black effect that man-made pollution has on these buildings. [7] The Parthenon is especially exposed and many of the remaining marbles are eroding to the point that they may no longer be identifiable. [8] The pollution from corrosive agents in the air has also attributed to this deterioration.
The third factor affecting ancient building conservation is tourism. While tourism provides both economical and cultural benefits, it can also be destructive. The Egyptian tomb of Seti the 1st is currently off limits to the public due to the deterioration that has been caused by tourists.[ citation needed ] The pyramids in Giza have also encountered problems due to large numbers of tourists; more tourists mean greater humidity and water presence, which can lead to erosion. [9]
All of the above factors complicate the conservation options available to treat these buildings.
The first step in any building conservation project is a sensitive assessment of its history and merits. As noted architect Donald Insall states, "Every building has its own biography. A knowledge of the whole life of a building brings an essential understanding of its features and its problems. [10] He gives the Parthenon in Athens as an example; built between 447 and 432 BCE to serve as a temple dedicated to the goddess Athena, its purpose over time changed to Christian church, mosque, and powder magazine before it became one of the most famous tourist attractions in the world.
Once the assessment is complete, the next step is a thorough measured survey with a tape, rod and level. Modern measuring techniques, such as photogrammetry (the use of aerial photographs to make maps and surveys) and stereophotogrammetry, are also used today to increase accuracy. Once the measurements are complete, there is an analysis of the structural stability of the building and its living pattern of movement. No building is permanently still; soil and wind can affect building stability and need to be documented. Finally, the architect or surveyor tests the electrical connections, plumbing, and other utilities present in the building (this is more for historic and re-purposed buildings). For both ancient and historic buildings, lightning conductors and fire-fighting equipment are checked to make sure they can provide sufficient protection. [11]
At the end of this assessment process, the conservator will analyze all the collected data and decide on a conservation plan based on available funding sources..
The phrase covers a wide span of activities, from the cleaning of the interior or exterior of a building — as took place at St Paul's Cathedral in London — to the rebuilding of damaged or derelict buildings, such as the restoration of the Windsor Great Hall in Windsor Castle after a destructive fire in 1992. The 1985–1989 removal of 38 layers of paint and the cleaning and repair of the exterior sandstone walls of the White House in the United States are an example of building restoration. [12]
Buildings are structures which have, from time to time, particular purposes. They require ongoing maintenance to prevent them falling into disrepair as a result of the ravages of time and use. Building restoration can be thought of as that set of activities which are greater than year-to-year maintenance, but which by retaining the building are less than a demolition and the construction of a new building.
Not all building conservation seeks to follow the original design of the building. It is reasonably commonplace for the shell of a building — its external walls — to be retained whilst an entirely new building is constructed within. This approach is also referred to as adaptive reuse.
Although techniques of architectural conservation are improving, the action of cleaning or repairing buildings can, with hindsight, be seen to cause problems that at the time were unforeseen. A good example is the unrestrained use of sandblasting to clean smog deposits from soft-stoned buildings — a technique employed in the UK in the 1960s and 1970s — which has damaged the external faces of stonework to the extent that in some cases, later, the stonework has needed to be replaced. Contemporary building codes recognize such problems, and (it is to be hoped) mitigate poor outcomes.
Most ancient buildings are constructed of stone and have survived from antiquity as a result of the stability of this building material. However, stone can deteriorate rapidly without protection, particularly in the modern era of pollution and climate change.
There are many organizations that work to raise public awareness of the necessity to preserve ancient and historic buildings and areas, across communities, users and government. In addition to promoting the cultural value of these buildings, and encouraging appropriate policies and strategies for conservation, the organizations can help in raising the required funding to implement conservation initiatives and plans, and often serve as a link between the community and local/federal governments to advance conservation projects. A brief list of architectural conservation organizations is below:
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Building restoration describes a particular treatment approach and philosophy within the field of architectural conservation and historic preservation. It emphasizes the preservation of structures such as historic sites, houses, monuments, and other significant properties through careful maintenance and upkeep. Restoration aims to create accurate depictions of these locations and protect them against deterioration that could make them inaccessible or unrecognizable in the future.
In the field of historic preservation, building restoration is the action or process of accurately revealing, recovering or representing the state of a historic building, as it appeared at a particular period in its history, while protecting its heritage value. Restoration work may be performed to reverse decay, or alterations made to the buildings.
Since Historic Building Conservation is more about fostering a deep appreciation for these famous structures and learning more about why they exist, rather than just keeping historic structures standing tall and looking as beautiful as ever, true historic building preservation aims for a high level of authenticity, accurately replicating historic materials and techniques as much as possible, ideally using modern techniques only in a concealed manner where they will not compromise the historic character of the structure's appearance. [19]
For instance a restoration might involve the replacement of outdated heating and cooling systems with newer ones, or the installation of climate controls that never existed at the time of building after careful study. Tsarskoye Selo, the complex of former royal palaces outside St Petersburg in Russia is an example of this sort of work.
Exterior and interior paint colors present similar problems over time. Air pollution, acid rain, and sun take a toll, and often many layers of different paint exist. Historic paint analysis of old paint layers now allow a corresponding chemical recipe and color to be re-produced. But this is often only a beginning as many of the original materials are either unstable or in many cases environmentally unsound. Many eighteenth century greens were made with arsenic and lead, materials no longer allowed in paints. Another problem occurs when the original pigment came from a material no longer available. For example, in the early to mid-19th century, some browns were produced from bits of ground mummies. In cases like this the standards allow other materials with similar appearance to be used and organizations like Britain's National Trust for Places of Historic Interest or Natural Beauty will work with a historic paint color re-creator s to replicate the antique paints in durable, stable, and environmentally safe materials. In the United States the National Trust for Historic Preservation is a helpful resource. The polychrome painted interiors of the Vermont State House and Boston Public Library are examples of this type of heritage restoration.
Historical conservation is the "preservation and repair of archaeological, historical, and cultural sites and artifacts". [20] When dealing with building conservation, there are four primary types of treatment, or ways in which a property can be managed. Each one has their own objectives and limitations. [21]
The next two treatments are a subset of preservation with some variation to account for the different requirements of the building and the needs of the institution.
The reasons to restore a building most frequently fall into five main categories. [23]
Value - Buildings hold intrinsic value not only in the history of the building, how it was used, but also how it was built. Historic buildings, notably pre-WWII, are built with higher quality materials and built under different standards than modern buildings.
Architectural Design - Buildings have personalities, specific architectural elements that make the building unique and more valuable. Saving these unique traits within original building are ideal.
Sustainability - Historic buildings store a lot of embodied energy. [24] Hence, it is better to preserve or re-use them rather than demolition. Restoring a building for another purpose than its original intent is called adaptive reuse. Financially, businesses are better off restoring a building and adapting it for modern use than constructing a new site. The buildings are often built to better standards and as mentioned above have unique architectural elements that can increase business.
Cultural significance - One of the most important reasons that a site is restored is because of its cultural significance. Certain sites are tied to a nation’s identity making the site more valuable for what it provides to the culture than if it were demolished. According to Building Talk, “the renovation of heritage buildings is essential to the permanent residence of history and culture in the nation’s psyche.” [25]
One chance rule - When a building is demolished what is lost cannot be measured. The site could hold a one of a kind design element or a historically significant past currently unknown. The One chance rule is guided by the idea that there is only one chance to restore a site and missing that opportunity could destroy a site of unknown significance. [25]
Although rare, there are times when a site would be demolished or reconstruction is chosen over restoration. This decision is made primarily when the resources to restore the site are unavailable. The challenge to reconstruction is that there is an element of conjecture in the process that can easily alter the site unintentionally. [26] Another reason not to restore a building is the value and knowledge that can be gained from the material remaining within the building. The Society for the Protection of Ancient Buildings has a unique approach to the preservation of historic buildings, which focuses on the materials that were used in the building's construction and what knowledge can be learned from the remaining material. [27]
One of the biggest challenges to building restoration is that each country has their own terminology, standards, regulations and oversights which impact every restoration process. As a result, there are no international set of standards. [28] Conservators often follow best practices in the restoration approach. Every restoration project will adhere to the standard that the property is to be used as it was originally intended. This standard will guide all other decisions in the restoration process. This would include which materials are selected, to methods of construction, and finishing touches to the building such as fixtures. The property being restored is considered a record of its time. Any work undertaken will only be to restore the site to the specified time period and no removal of those historical elements will be made, however this does not exclude removing elements not historically accurate to the site. [29]
Best practices are as follows:
Cultural heritage sites
Cultural Heritage is the physical and emotional reflection of a society, their legacy, and what they value. Tangible or physical representations include the material of the culture, locations of cultural significance, and the community associated with the culture. Intangible representations include oral stories, traditions, and the emotional connection to the cultural ancestors. [37] The conservation and restoration of cultural heritage sites pose different challenges and often follow different guidelines because of designation of a heritage site. The United Nations Educational, Scientific and Cultural Organization (UNESCO) is a guiding resource in the conservation of cultural heritage sites. UNESCO's mission is to identify, protect, and preserve World Heritage Sites. The World Heritage List is constantly evolving as new sites of cultural significance are added. [38] Another great resource for restoration of cultural heritage sites is the World Monuments Fund, which focuses on working with local groups around the world providing support for restoration, preservation, and stewardship. [39]
Restoration of Historic Buildings
Restoration of historic buildings varies from country to country, just as with cultural heritage sites and other building restoration projects. Before any work is done on a historic building, conservator-restorers should consult local requirements. Best practices listed above still apply. One example of restoration of historic buildings is the work conducted by the National Park Service which owns and maintains thousands of historic buildings and has been a leader in historic preservation for over 100 years. The standards were developed in 1975 and updated in 1992. [40] The standards deal with the "...materials, features, finishes, spaces, and spatial relationships..." [41] of historic buildings and are divided into preservation, rehabilitating, restoration and reconstruction.
As buildings can sustain various forms of damage and deterioration over time, understanding the cause of this damage and finding the best way to treat and prevent it is an important aspect to building restoration. The Agents of Deterioration are the ten primary sources of damage to heritage objects and buildings comprised in a comprehensive list by the Canadian Conservation Institute. The Agents are physical forces, fire, pests, light (ultraviolet and infrared), incorrect relative humidity, thieves and vandals, water, pollutants, incorrect temperature and the dissociation of objects. [42] While each of the ten agents can affect a historic building, some agents cause more common types of damage that may be addressed through building restoration.
With respect to cultural property, conservation science is the interdisciplinary study of the conservation of art, architecture, technical art history and other cultural works through the use of scientific inquiry. General areas of research include the technology and structure of artistic and historic works. In other words, the materials and techniques from which cultural, artistic and historic objects are made.
A conservator-restorer is a professional responsible for the preservation of artistic and cultural artifacts, also known as cultural heritage. Conservators possess the expertise to preserve cultural heritage in a way that retains the integrity of the object, building or site, including its historical significance, context and aesthetic or visual aspects. This kind of preservation is done by analyzing and assessing the condition of cultural property, understanding processes and evidence of deterioration, planning collections care or site management strategies that prevent damage, carrying out conservation treatments, and conducting research. A conservator's job is to ensure that the objects in a museum's collection are kept in the best possible condition, as well as to serve the museum's mission to bring art before the public.
Historic paint analysis, or architectural paint research, is the scientific analysis of a broad range of architectural finishes, and is primarily used to determine the color and behavior of surface finishes at any given point in time. This helps us to understand the building's structural history and how its appearance has changed over time.
The Getty Conservation Institute (GCI), located in Los Angeles, California, is a program of the J. Paul Getty Trust. It is headquartered at the Getty Center but also has facilities at the Getty Villa, and commenced operation in 1985. The GCI is a private international research institution dedicated to advancing conservation practice through the creation and delivery of knowledge. It "serves the conservation community through scientific research, education and training, model field projects, and the dissemination of the results of both its own work and the work of others in the field" and "adheres to the principles that guide the work of the Getty Trust: service, philanthropy, teaching, and access." GCI has activities in both art conservation and architectural conservation.
Stained glass conservation refers to the protection and preservation of historic stained glass for present and future generations. It involves any and all actions devoted to the prevention, mitigation, or reversal of the processes of deterioration that affect such glassworks and subsequently inhibit individuals' ability to access and appreciate them, as part of the world's collective cultural heritage. It functions as a part of the larger practices of cultural heritage conservation (conservation-restoration) and architectural conservation.
Conservation and restoration of metals is the activity devoted to the protection and preservation of historical and archaeological objects made partly or entirely of metal. In it are included all activities aimed at preventing or slowing deterioration of items, as well as improving accessibility and readability of the objects of cultural heritage. Despite the fact that metals are generally considered as relatively permanent and stable materials, in contact with the environment they deteriorate gradually, some faster and some much slower. This applies especially to archaeological finds.
Conservation and restoration of movable cultural property is a term used to denote the conservation of movable cultural property items in libraries, archives, museums and private collections. Conservation encompasses all the actions taken toward the long-term preservation of cultural heritage. Activities include examination, documentation, treatment, and preventive care, which is supported by research and education. Object conservation is specifically the actions taken to preserve and restore cultural objects. The objects span a wide range of materials from a variety of cultures, time periods, and functions. Object conservation can be applied to both art objects and artifacts. Conservation practice aims to prevent damage from occurring, a process known as 'preventive conservation'. The purpose of preventive conservation is to maintain, and where possible enhance, the condition of an object, as well as managing deterioration risks, such as handling and environmental conditions. Historically, object conservation was focused on the category of fine arts but now many different types of objects are conserved. Each type of object material, typically denoted by organic or inorganic then the specific medium, requires a specialized professional conservator and often requires collaborative work between museum staff, scientists, and conservators.
A paintings conservator is an individual responsible for protecting cultural heritage in the form of painted works of art. These individuals are most often under the employ of museums, conservation centers, or other cultural institutions. They oversee the physical care of collections, and are trained in chemistry and practical application of techniques for repairing and restoring paintings.
The conservation and restoration of books, manuscripts, documents, and ephemera is an activity dedicated to extending the life of items of historical and personal value made primarily from paper, parchment, and leather. When applied to cultural heritage, conservation activities are generally undertaken by a conservator. The primary goal of conservation is to extend the lifespan of the object as well as maintaining its integrity by keeping all additions reversible. Conservation of books and paper involves techniques of bookbinding, restoration, paper chemistry, and other material technologies including preservation and archival techniques.
A photograph conservator is a professional who examines, documents, researches, and treats photographs, including documenting the structure and condition of art works through written and photographic records, monitoring conditions of works in storage and exhibition and transit environments. This person also performs all aspects of the treatment of photographs and related artworks with adherence to the professional Code of Ethics.
The conservation and restoration of wooden furniture is an activity dedicated to the preservation and protection of wooden furniture objects of historical and personal value. When applied to cultural heritage this activity is generally undertaken by a conservator-restorer. Furniture conservation and restoration can be divided into two general areas: structure and finish. Structure generally relates to wood and can be divided into solid, joined, and veneered wood. The finish of furniture can be painted or transparent.
The conservation and restoration of archaeological sites is the collaborative effort between archaeologists, conservators, and visitors to preserve an archaeological site, and if deemed appropriate, to restore it to its previous state. Considerations about aesthetic, historic, scientific, religious, symbolic, educational, economic, and ecological values all need to be assessed prior to deciding the methods of conservation or needs for restoration. The process of archaeology is essentially destructive, as excavation permanently changes the nature and context of the site and the associated information. Therefore, archaeologists and conservators have an ethical responsibility to care for and conserve the sites they put at risk.
The conservation and restoration of clocks refers to the care given to the physical and functional aspects of time measuring devices featuring "moving hands on a dial face" exclusive of watches. Care for clocks constitutes regulating the external environment, cleaning, winding, lubrication, pest-management, and repairing or replacing mechanical and aesthetic components to preserve or achieve the desired state as specified by the owner. Clocks are typically composed of multiple types of materials such as wood, metal, paint, plastic, etc., which have unique behaviors and environmental interactions, making treatment options complex. The materials used and the complexity of clockwork warrant having a Horological Conservator complete the work.
The conservation and restoration of painting frames is the process through which picture frames are preserved. Frame conservation and restoration includes general cleaning of the frame, as well as in depth processes such as replacing damaged ornamentation, gilding, and toning.
The conservation and restoration of paintings is carried out by professional painting conservators. Paintings cover a wide range of various mediums, materials, and their supports. Painting types include fine art to decorative and functional objects spanning from acrylics, frescoes, and oil paint on various surfaces, egg tempera on panels and canvas, lacquer painting, water color and more. Knowing the materials of any given painting and its support allows for the proper restoration and conservation practices. All components of a painting will react to its environment differently, and impact the artwork as a whole. These material components along with collections care will determine the longevity of a painting. The first steps to conservation and restoration is preventive conservation followed by active restoration with the artist's intent in mind.
The conservation and restoration of lighthouses is when lighthouse structures are preserved through detailed examination, cleaning, and in-kind replacement of materials. Given the wide variety of materials used to construct lighthouses, a variety of techniques and considerations are required. Lighthouses alert seagoers of rocky shores nearby and provide landmark navigation. They also act as a physical representation to maritime history and advancement. These historic buildings are prone to deterioration due to their location on rocky outcrops of land near the water, as well as severe weather events, and the continued rise of sea levels. Given these conditions preservation and conservation efforts have increased.
The conservation and restoration of ancient Greek pottery is a sub-section of the broader topic of conservation and restoration of ceramic objects. Ancient Greek pottery is one of the most commonly found types of artifacts from the ancient Greek world. The information learned from vase paintings forms the foundation of modern knowledge of ancient Greek art and culture. Most ancient Greek pottery is terracotta, a type of earthenware ceramic, dating from the 11th century BCE through the 1st century CE. The objects are usually excavated from archaeological sites in broken pieces, or shards, and then reassembled. Some have been discovered intact in tombs. Professional conservator-restorers, often in collaboration with curators and conservation scientists, undertake the conservation-restoration of ancient Greek pottery.
The conservation-restoration of panel paintings involves preventive and treatment measures taken by paintings conservators to slow deterioration, preserve, and repair damage. Panel paintings consist of a wood support, a ground, and an image layer. They are typically constructed of two or more panels joined together by crossbeam braces which can separate due to age and material instability caused by fluctuations in relative humidity and temperature. These factors compromise structural integrity and can lead to warping and paint flaking. Because wood is particularly susceptible to pest damage, an IPM plan and regulation of the conditions in storage and display are essential. Past treatments that have fallen out of favor because they can cause permanent damage include transfer of the painting onto a new support, planing, and heavy cradling. Today's conservators often have to remediate damage from previous restoration efforts. Modern conservation-restoration techniques favor minimal intervention that accommodates wood's natural tendency to react to environmental changes. Treatments may include applying flexible battens to minimize deformation or simply leaving distortions alone, instead focusing on preventive care to preserve the artwork in its original state.
The Conservation of South Asian household shrines is an activity dedicated to the preservation of household shrines from South Asia. When applied to cultural heritage, held by either museums or private collectors, this activity is generally undertaken by a conservator-restorer. South Asian shrines held in museum collections around the world are principally shrines relate to Hindu, Jain, or Buddhist households. Due to their original use and sacred nature, these shrines present unique conservation and restoration challenges for those tasked with their care.
The conservation and restoration of quilts refers to the processes involved in maintaining the integrity of quilts and/or restoring them to an acceptable standard so that they may be preserved for future generations. Quilts have been produced for centuries, as utilitarian blankets, decorations, family heirlooms, and now treasured museum collections objects. Quilts are three-layered textile pieces with a decorated top, a back, and a filler in the middle. The composite nature of these objects creates an interesting challenge for their conservation, as the separate layers can be made of different textile materials, multiple colors, and therefore, varying degrees of wear, tear, and damage.