Conservation of historic buildings and monuments

Conservation of historic buildings and monuments Introduction Throughout the renaissance period, preservation and restoration remained an experimental process in which many of the tools, instruments and methods were selected at random. The process was pursued with very little critical or historical understanding. This led to many architects such as Viollet-le-Duc, Sir George Gilbert Scott, John Ruskin and William Morris voicing their perceptions of how preservation and restoration should restore buildings to how they would have appeared in their prime. Most of our modern principles of conservation arose from the ideas of John Ruskin and William Morris from the mid 19th century. They stated how we are merely custodians of the buildings left form our predecessors for our future generations. They also state how our intervention in historic buildings must be kept to a minimum and how continued repair and maintenance of these historic buildings must be valued. These ideas form the basis of modern perception of preservation and restoration of our valued historic buildings and monuments. What is Conservation? Conservation is a way of planning designed to conserve historic buildings, areas and monuments in an effort to connect a places historical background to its population and primarily its culture. Conservation is means of green building, that is, reusing the existing building as oppose to new construction for a modern purpose and use. The four main styles of conservation of historic buildings are preservation, rehabilitation, reconstruction and restoration. Preservation Preservation is the means of keeping an historic building a close as possible to its original state by means of continued repair and maintenance. This focuses on the stabilization and repair of the existing materials in the building and the retention of a buildings state as it has evolved over time. Restoration Restoration of historic buildings involves reconstructing parts of the building that have fallen into decay as imitations of the highest possible quality of the original building. This form depicts a building at one stage in time and often removes any evidence of any other period in which the building existed. Rehabilitation Rehabilitation sees the need to alter or extent to an historic building to meet modern demands while still keeping the historical character of the building. Reconstruction Reconstruction re-creates vanished buildings or parts of buildings by interpretive means. Criticisms of Conservation Like many developments in urban design and planning, conservation has had its share of negative perceptions. Such aspects if this criticism include; Cost Style Mistakes made Cost implications of Conservation There are many costs associated with the preservation or restoration of an historic building. Often they need specialist workmanship which can be both time and money consuming on a construction project. Delicate elements of the building often require propping or some sort of support which can take up valuable space on site. Many of the systems in an old building need upgrading which can be difficult to install. Requirements such as energy rating and fire certificates can be hard to upgrade as often the original design of the building did not consider such modern ideas. Elements such as cavity walls or wood cladding are expensive and difficult to bring up to modern standards regarding these requirements. Structural elements of an historic building are the most endeavouring aspects of the conservation process to get right. Foundations are a recurring issue with many of the buildings as newer structures with deeper and heavier foundations can often cause uplift of the older building. Th e cost of repairing the foundations of these buildings are astronomical so diligent design of new foundations and monitoring of existing buildings is paramount during construction. All this adds up on a construction project which has undesired implicated cost for both contractor and engineer. Modern style construction Due to property price rises and limitation of space in city centres our society has constructed its buildings higher and higher to meet its purposes. This popular style of higher buildings can often cause the older, smaller historic buildings to become dwarfed and ultimately undesirable for its occupants. As the push towards increased numbers of taller sky-scrapers in urban areas is inevitable, this leaves many of the smaller older buildings redundant. Critics also say that the older historic buildings cannot accommodate as many people or businesses as newer developments can. This increases the rent on these buildings and causes low income retailers and residents to relocate. This has a negative impact on a city centre regarding retailing. Mistakes in conservation Another criticism of conservation is that it is very susceptible to mistakes being made which are ultimately to the determent of the building. Inappropriate renovations can cause damage to buildings and put it worse off than it was before. According to the Tipperary county council website some of the most common mistakes made in small scale conservation in the area are; Removal of old 18th or 19th century windows to be replaced with new PVC, plastic or aluminium windows The removal of original slate and the replacement with imitation slate or tiles The removal of the render. The website says how these changes can affect the ventilation systems in the building and can exacerbate any decaying or rotting that is taking place in the building. Removal of render and replacing it with modern Portland cement which is a lot harder can cause cracking, admit moisture and trap it within the wall. This is just an example of a few of the mistakes that can be made during the renovation process. It is clear that a great responsibility is undertaken in conducting a conservation of a building. It is the utmost importance that the right techniques and products are investigated as to preserve the building and not to amplify or created any problems with the building or monument. Sustainability of conservation Historic buildings are inherently sustainable. The correct preservation can maximise the use of the existing materials and infrastructure and in return reduces waste caused by demolition and energy put into the production of new materials and construction. Many of the old buildings were designed with sustainability in mind. Many features of historic buildings were built with aspects like climate and site situation in mind to give a sustainable build. If correctly conserved, many old buildings can serve future generations for many years to come. Conservation versus New Construction Preserving a building is often referred to as the ultimate recycling project. Although, as I have already outlined it has its many sceptics who say that historic buildings are beyond their use and require significant corrective measure to make them viable as a functioning structure. However, Green and sustainable design has become ever more popular in todays new construction and preservation industries. A major aspect to this is the reduction in carbon that conservation brings when compared with new construction. Concrete products, steel, transportation, heating and electricity are the main factors contributing to a projects overall carbon emissions. Conservation of old buildings drastically cuts down on new concrete products and their inherent transportation costs as well as the use of electricity to operate plant that is associated with new construction. Conservation versus Demolition The conservation of old buildings is a much more sensible option than demolition in relation to sustainability. There are many times when a building is deemed structurally unsound and the need for demolition is unrivalled in the interest of public safety but this should not prevent our society from conserving many of our old buildings for continued use. Conserving greatly reduces the amount of construction material being dumped in landfill. Demolition creates vast amount of crushed concrete and stone that is often unusable for construction again. Ethics and conservation I have decided to divide ethics and conservation into two sub-headings that I will discuss, they are Ethics of conservation Ethics within conservation. Ethics of conservation Preservation of historic buildings and monuments plays a vital role in the growth of our civilization. It is oftentimes easy to disregard the accomplishments of past generations as we strive to change our societies and environments to be more suited to our present needs. John Ruskin (1819-1900) was one the first to develop the conservation movement whose ideals were that a historic building, painting or sculpture is a unique creation by an artisan or artist in a specific historic context. He believed that such genuine works of art resulted from personal sacrifice and it was based on mans perception of beauty on nature, where in itself existed as a reflection of god. (Jukka Jokilehto, A History of Architectural Conservation, 1999, page175) Such ideals led to him becoming a pioneer in help organise preservation of historic buildings and monuments writing many works on the subject. His principles form the basis on conservation in todays world where we see historic buildings and monuments as a link to our past and our culture. With ongoing development of our city centres and transportation networks it would be very easy to demolish the outdated and often useless buildings and monuments that get in our way. Therefore, the question arises why dont we? Conservation is an ethical subject with the decision to neglect our revered buildings and monuments a conscientious one. As John Ruskin said many of our monasteries and churches alike are works of art in the reflection of god. It is often said that age in itself contributes to beauty. Age is a thing that is associated with wisdom and many of our historic buildings add a feeling of intellect and enlightenment to an area. Often, historic conservation of city centre can help them become more competitive with regard to retailing and business as historic, unique buildings give areas more prominence in comparison to the homogeneous skyscrapers that dominate the skylines of many of our large cities. Ethics within conservation There are many ethical values within conservation itself that regulates the nature of the industry. As one would expect it is a delicate subject whether or whether not to intervene with the natural state of a revered building or monument. Therefore, many charters and polices have been developed and implemented over the years. The first time that an international agreement was made on the principles of conservation was the Athens charter of 1931. The charter was later review and update with the Venice Charter in 1964 which relates to historic buildings, the Burra charter which deals with places of historic significance and the Washington Charter which is relates to historic towns and districts. These charters were drafted by The International Committee for Monuments and Sites (ICOMOS). Conservation is regarded as the work done to prevent further decay of a building and to extend its life. Conservation can often be undertaken with the greatest of enthusiasm and best intentions. However, the conservation process should be carried out so that no damage is done to the building and no falsifying or destruction of historical evidence occurs. Lack of information or the use of incorrect in inappropriate techniques can often unintentionally cause both, aesthetic and structural damage. According to (http://www.environ.ie/en/Publications/Heritage), the main principles in these charters to help prevent unintentional damage from occurring are; Retention or restoration of historical significance Conservation process based on research Minimum physical intervention Maintenance of visual setting These are the basic principles outlined in the charters which help instil ethical practice of conservation works. Case Studies In this section I will report on two case studies which I researched which will highlight mistakes made in the past, ethics in conservation and the sustainability of conservation. The leaning Tower of Pisa The leaning tower of Pisa is one of Italys most infamous land marks. It attracts hundreds of thousands of tourists every year. Construction of the tower began in 1173 after a period of prosperity in Pisa. The tower began to sway soon after the beginning of construction due to a poorly laid foundation and loose substrate that has allowed the foundation to shift direction. The tower was built in three stages over 177 years. The tower began to sink after construction was completed on the third floor. In 1272 construction was resumed with architect Giovanni di Simone deciding to build one side taller than the other to compensate for the tilt. This caused the tower to lean the other way resulting in the tower having a curved shape. The curve and 3.97o angle to the vertical at which the tower leans caused inherent damage to structural elements of the tower as well as aesthetic damage. This led to the Italian government to seek international aid to prevent the tower from collapsing on February of 1964. They did, however, declare that they desired to retain a certain degree of the towers tilt because of it tourism viability. Many attempts were made to rectify the foundations. Deformations were made in the soil through vertical anchorages and forces were applied using weights. This was one of the most simplistic solutions but also the most ineffective as it only resulted in inducing further compression on the soil. This caused extensive damage to the tower where cracking and splitting of many of the mall columns occurred. In 1993 900 tonnes of lead weights were applied to oppose the tilt of the structure. Additional provisional strengthening of the structure was applied with a series of circumferential steel cables. The final measure in the stabilization of the structure is to be a new technique called under-excavation. This technique consists in pulling out, about 5 m under the upstream border of the foundation, small amounts of soils, through a series of casings drilled into the soil. (www.sciencedirect.com). This it is hoped will gently cause the tower to tilt towards its desired inclination without disturbing the fragile columns in the structure. The leaning tower of Pisa is an example of restoration attempts where experimental methods were used with almost dire consequences for the building. However, an ethical approached was undertaken which was based on research and an effort to minimize distortion of the appearance of the building. The Parthenon Besides the pyramids at Giza, the Parthenon is one of most revered monument in the world. It was built between 447 432 BC by Greek architects Ictinus and Callicrates. The structure underwent extensive damage over an extended period time. In 296 BC gold from the statues in the building was removed by the general Lachares to pay his army. In the 5th century AD the temple was converted into a Christian church. In 1460 it housed a Turkish mosque and in 1687 gun-powder stored by the Turks inside the temple exploded and destroyed the central area. (www.archive.com). A recent major influence in the increased deterioration of the monument has been the expansion and development of nearby Athens. Urbanization has caused increased amount of carbon dioxide in the air which has contributed to more intense acid rain. This has seriously affected the monument more so in the last 30 years than in the previous eighteen centuries. In 1975 the Greek government made a special effort to try and restore the Parthenon to some of its former glory. After some delay, a committee was set up in 1983 which later received funding from the European Union to carry out its works. It was investigated that some of the earlier works were incorrect and therefore carefully dismantled and a restoration process commenced. The preservation firstly involved rectifying mistakes made by conservationists in the past. Steel beams were places within the stone structure to help support it but these were not coated in lead and inevitably rusted. The rusted beams expanded and cause the stone to crack more than it was so previously. It is impossible to restore the building to exactly how it was built first day but the aesthetics of the building were preserved by replacing any missing columns and lintels with precisely cut marble from the original quarry. The overall idea behind the conservation attempt is to replace all missing pieces of marble in the structure where they would have been preserving the structural integrity of the building by supporting these with modern materials. The preservation of the Parthenon shows a standard of ethics that Ruskin and Morris adhered to. Although there were mistakes made in the past, a willingness to restore the monument to its former glory while still keeping the style of the original building intact is the way it should be done. Preserving this monument is paramount as it has a clear link to the nation of Greece and its culture and past. Future Ideas From researching this project it is clear to see that conservation of old buildings could prove extremely beneficial to society with regard to sustainable living. With a recent push towards eco-living, conservation of some of our older building as oppose to demolishing them and erecting a new structure would be a way forward. In my opinion, future policies could incorporate full structural analysis to look for potential conservation processes before any building is demolished. This could be especially beneficial in city centres where construction of new multi-storey buildings is quite challenging. Also, regular maintenance checks of all buildings, historic or recently built, should take place on a regular basis as to provide any preservation techniques that may need be applied. This would greatly help sustain the buildings we have and reduce the need for any new construction which would have a positive impact for the environment. References Websites http://www.nationaltrust.org.uk/main http://www.wbdg.org/resources/sustainable http://www.environ.ie/en/Publications/Heritage/ArchitecturalHeritage/ Conservation of historic buildings by Bernard m feilden, 1982 http://www.culture.gr/h/2/eh251.jsp?obj_id=912 Ioanna Venieri, archaeologist www.preservationnation.org