Evaluation of Occupational Safety in Restoration Projects of Historic Buildings: Risk Analysis with Selected Projects

Abstract

Restoration works in historical buildings, which have gained importance in Türkiye in recent years, have unique risks in terms of occupational safety. Employees in this sector are exposed to many different risks during the restoration of historical building projects, and ensuring occupational safety is an important problem for the sector. In order to find a solution to this problem, a comprehensive examination of historical building projects was made in terms of occupational safety during the restoration process. Within the scope of the study every stage of the three different restoration projects was examined in terms of occupational safety. In line with this research, job safety analysis was performed by dividing the steps in the restoration projects into groups. The risks in the construction sites were determined and precautions were presented to eliminate or reduce these risks. As a result, the risks that may occur during the restoration phase of a historical building are shown in detail together with the prevention methods. It is expected that if the stakeholders of restoration projects integrate the information presented into their occupational health and safety systems, it will contribute to the improvement in the processes and there will be a decrease in the frequency of work accidents.

1. Introduction

National organizations (Ministry of Culture and Tourism, Civil Society Organizations, Universities, etc.) and international organizations (UNESCO, ICOMOS, ICCROM, etc.) carry out various activities for the registration, documentation and protection of immovable cultural assets in the world and in Türkiye. The phenomenon of protecting cultural assets has become an increasingly important concept [1]. The number of immovable cultural assets registered by the Ministry of Culture and Tourism in Türkiye, which is a very rich geography in terms of immovable cultural assets, was determined as 122,144 by the end of 2022 [2]. In recent years, the increasing importance given to immovable cultural assets, which are the common heritage of humanity, has led to an increase in the protection activities to be carried out in this field.

The concept of protection can be defined as trying to prevent a negative change in the situation from the past to the present by showing the necessary attention and care to keep a person or an object away from external influences, dangers or a troublesome event [3]. According to Zakar (2015), protection is the understanding of repairing and improving a monument with the least intervention in accordance with its original condition by documenting it together with its surroundings, ensuring its continuous maintenance and use. The meaning of protection is the whole of cultural values that are transferred from the past to the present. Preserving the documents of that period in order to remember the past means preserving all the resources that we can benefit from. In historical artifacts, this definition is interpreted as inspecting the artifacts against destructive changes, preventing damage, and maintaining cultural concepts, traditions and customs.

In the past, “monumental buildings” were built to meet a common need of societies [4]. In order for these structures to have a high functional value, regular maintenance should be performed by adhering to their original state. In this way, the structure turns into a collection of information that will be transferred to future generations. In addition to this principle continuing to be valid today, structures that have lost their original function should be preserved to the present day while preserving their monumental values.

Restoration is one of the most basic elements of the concept of conservation. Restoration projects involve deliberate and systematic efforts to conserve and renew the historical, architectural, or cultural significance of a structure, object, or site [5,6]. These projects encompass activities like careful repair, reconstruction, or refurbishment of elements that have deteriorated or been damaged, guided by historical research and documentation to ensure the preservation of the subject’s original character and authenticity [7]. Restoration projects can encompass a wide range of assets, including buildings, artworks, monuments, and cultural landmarks, with the primary goal of safeguarding their heritage value while making them structurally sound and aesthetically faithful to their original design and purpose [8,9].

In the past, the only purpose of the repair was to keep the building standing and to preserve its formal integrity by rebuilding the destroyed parts. In addition to this understanding, continuing to use by making new additions according to changing living requirements is seen as ensuring functionality. However, today, historical buildings and monuments are considered as documents that indicate the architecture and urban structure, construction techniques and social conditions of the period in which they were built.

The most important difference between the restoration works carried out today compared to the past is that they are carried out by adhering to certain principles rather than personal opinions and suggestions and the architectural movements of that day. Although the history of conservation practices dates back to ancient times, restorations using scientific methods began in the 19th century. According to Viollet le -Duc, who has made important studies in order to carry out restoration applications with a scientific method, “…To restore a building is to turn it into a completed building at a certain time, as it never existed, instead of preserving it, repairing it, or making it again [10].

The biggest damages that occurred in the buildings during this period were that during the restoration process, the architects changed the original state of the monuments with designs that conformed to the first style, and the style of the period when the construction of the monuments started was accepted as valid and the additions reflecting the other period were completely removed. In conclusion; When carrying out conservation and restoration work in a historical building, the following elements should be taken into consideration [11].

The heritage value of a historic site should be preserved, and intact or repairable character identifying elements should not be removed or substantially altered.

• If its current location is a character defining element, particular attention should be paid to its harmony with the surrounding texture. For this reason, it is necessary to preserve the changes that become character defining elements on their own over time.
• An approach that requires minimal intervention during conservation should be adopted. For the intervention made during this approach, it is necessary to choose the tools that can cause the least damage to the structure.
• For the historic building, a type of use should be chosen that requires little or no change in the elements that define its character.
• While making all kinds of interventions necessary to preserve the physically and visually character-defining elements, it would be the best approach to document each data and intervention, which is especially compatible with the historical place and can be determined when viewed closely, for future reference.

The protection of cultural and natural assets, which form the basis of national cultural values, is important in terms of the protection of universal culture as well as the protection of national culture. In the protection of immovable cultural and natural assets, it is very important to first identify the structures to be protected and then carry out the registration processes correctly. Monumental structures and environmentally valuable structures can be classified as immovable cultural assets that need to be protected. In order for an immovable to gain a cultural asset value, it must have a unique value and this value must give the immovable certain qualities [12]. The protection of cultural assets is of international importance. For example, France has a stringent system for protecting historical monuments. The Ministry of Culture oversees preservation efforts, and properties are classified as Monuments Historiques. Restoration plans require approval, and the use of traditional materials is often encouraged [13]. The UK has various heritage protection laws, including the Planning (Listed Buildings and Conservation Areas) Act 1990. English Heritage and Historic Environment Scotland are key organizations overseeing heritage conservation [14]. Heritage protection in Sweden is managed by the Swedish National Heritage Board. Restoration projects are subject to planning regulations and local authorities’ approvals [15]. Italy has a robust legal framework for the protection of cultural heritage. The Italian Constitution and various laws and regulations provide the foundation for safeguarding historical and artistic heritage. The Ministry of Cultural Heritage and Activities is the central government body responsible for cultural heritage protection. It formulates policies, manages cultural resources, and oversees various cultural institutions and sites [16].

In Türkiye, there are studies on the architectural analysis of the first group of restored buildings, the techniques used before and during restoration [17,18,19,20]. There have also been studies on conservation principles and repair methods [21,22]. However, studies addressing the issue in terms of occupational health and safety are quite limited.

In fact, the application of existing occupational safety regulations in restoration projects is also highly relative. The adoption of safety regulations in restoration projects, or any type of project, can be influenced by various factors, leading to instances where these regulations are not fully implemented. First and foremost, a significant issue may be a lack of awareness among project stakeholders, including contractors and project managers, regarding the specific safety regulations applicable to restoration projects. Ignorance of these regulations can result in unintentional non-compliance. Additionally, the cost considerations associated with adhering to safety regulations play a crucial role. Implementing safety measures often necessitates additional resources, such as personal protective equipment (PPE) and safety training, which can raise concerns about increased project costs. Moreover, restoration projects often face stringent time constraints, and the strict enforcement of safety regulations may be perceived as a hindrance to meeting deadlines. Consequently, project managers might feel pressure to cut corners or bypass safety measures to expedite the project. Lack of enforcement of safety regulations is another significant factor.

Reyers and Mansfield (2001), indicate that it is difficult to predetermine the extent, duration and cost of conservation refurbishment projects [23]. Restoration works are unique and non-duplicable. Restoration projects are also unique in terms of occupational health and safety, additionally to the methods applied and the processes followed. A historical building to be restored is much more vulnerable than standard buildings because it is in a late period of its life cycle. In addition to preserving the originality of these structures, situations such as lack of material knowledge, uncertainty of the construction techniques used, and lack of expert workforce pose significant risks [24]. Additionally, to cover the whole range of new building construction activities, restoration activities involve hazards that are difficult or impossible to encounter in most construction projects. Therefore, it is very important to examine restoration projects in terms of occupational health and safety.

In the study, sample restoration projects containing different hazards were examined and as a result of the risk analysis, information was given about the measures to be taken to ensure occupational health and safety in the restoration of historical buildings. In addition, possible risks that may be encountered during architectural restoration activities were examined and analyzed in terms of physical, chemical, biological and ergonomic factors, taking into account legislative obligations and based on information based on observational data in the construction site. In the study, the Job Hazard Analysis method was selected as the risk analysis method. The flowchart of applied methodology is presented in Figure 1.

2. Occupational Safety and Potential Hazards in Historic Buildings

The science of occupational health and safety is a set of systematic studies carried out in order to ensure that the activity carried out in the workplaces can continue without any problems and to protect from the dangers arising accordingly, from the conditions that will have negative effects on the safety and health of the employees and to provide a more workable work environment. This branch of science covers not only the protection of the employee, but also the conditions for protecting the workplace, its affiliates and the environment and surroundings in which the work is carried out.

In the construction sector, the most common type of accident is falls from height. Akboğa and Baradan (2020) found that “falls” and “struck by falling object” were the two most noticeable data with 36.4% and 30.0% frequencies, respectively [25]. These findings show similarities with past studies. Many researchers pointed out that fall accidents are not only the most frequent in the construction, but also their results are more severe [26,27,28]. Similarly, Arndt et al. found that being struck by falling objects is one of the common causes of fatal injuries in the construction industry [29]. Haslam et al. also indicated that the majority of construction fatalities in Great Britain resulted from falls from height (46%) and being struck by a moving vehicle (15%). The most common causes of major injuries were falls from height (31%); slips, trips or falls on the level (25%); and being struck by a moving/falling object (17%) [30]. Hoonakker et al. (2005) and Chi et al. (2005) also describe the situation in other countries, revealing a similar pattern [26,31,32].

Restoration works, with its broad definition, involves making the most appropriate interventions without deviating from its original state by providing protection and repair to a historical building, which is currently standing in whole or in part, in light of all damage and available data (photographs, documents, etc.). Since the existing structure has authentic value and this authenticity has to be preserved, the context and schedule of the work has to depend on different sensitivities [33]. Also, it is very difficult to establish a certain standard in the restoration of a historical building. Because each project should be evaluated within its own unique conditions [5]. However, the measures taken against the risk faced are clear in accordance with the legislation and it is possible to make generalizations about how they can be implemented in practice. It is very difficult to create a work program in these projects, where techniques that differ from modern construction techniques in many ways are used, and there are many uncertainties in the structure, and it can be revised many times during the restoration phase. In addition, many parameters that need to be considered in every historical building make it difficult to ensure occupational safety in a historical building.

Although the restoration of historical buildings is considered in the category of construction works, it is among the practices that should be handled separately in terms of occupational safety due to its specificity [1,25]. For this reason, occupational health and safety measures taken in the restoration of historical buildings should not be limited to the measures taken in construction works. In order for restoration projects to be completed safely, in addition to the restorers, conservators, architects, engineers, application supervisors, etc., in the team, OHS officers must be involved before and during the construction process. In restoration works, studies and interventions that include the hazards identified in the analysis results and proactive solutions to be made to them are of great importance. The specific risks of restoration projects can be seen in Figure 2.

Uncertainty of the Construction Site—The definition and boundaries of the “construction site” in restoration construction work are quite uncertain and variable. It is seen that restoration construction works are frequently carried out in areas where the public and traffic flow are dense, where tourism activities increase due to the old structure, and in areas located in the historical urban fabric with narrow street formation from the past. Therefore, a construction site environment with defined boundaries and security measures, as in the construction of a new building, is not possible in restoration projects.

Structural Damage—In restoration works, it is generally necessary to determine the damage or the cause of this damage in the protected buildings and to determine the way of intervention to the building. Most of the damage in buildings can be caused by ground-related reasons such as the use of wrong materials, poor workmanship, deterioration of the material used over time and fire. From this point of view, OHS in restoration works is a process that should be planned from the documentation of the building or building group. Static control of the building is the first stage to be considered in the implementation phase of restoration. Damage to the structural system in protected buildings can be accepted as a reason for the building to enter the restoration process. Such problems in the building pose additional risks for the workers during the retrofitting works. Because when retrofitting works start in the building, other construction activities are often carried out. This situation causes the intersection of works with different risks and the emergence of unforeseen risks [5].

Scaffolding Installation—Scaffolding is required for similar activities such as cleaning and repairing the facades of historical buildings, lead renewal on roofs, etc. As in the construction of a new building, scaffolding in restoration works should be designed by thinking together with the process during the application phase. In restoration activities, the walls of the building, which are known and whose safety cannot be assured, and which should be preserved in their original form as a historical document, constitute an obstacle to fixing the scaffolding to the wall and placing temporary anchoring equipment there. In addition, while protecting and restoring the existing historical structure, it is often not possible to anchor the scaffolds to the building surface due to the damage to the texture and static problems.

Biological Risks—Biological risks arising from dead animals (such as bats, mice) and pests, such as insects that damage the wood inside the buildings, show how different the working environment in restoration activities is from other business lines. In addition, biological risk factors such as some plants (such as nettles or thorny plants), gnawing animals, insects (such as scorpions, fleas) that have formed in the building over time should also be identified [34].

Asbestos—Asbestos is a fireproofing and thermal insulation material that used to be a prominent element of building construction before it was banned in many countries [35]. Because of its characteristics, asbestos was added to concrete, asphalt, vinyl materials in roof shingles, pipes, siding, wall board, floor tiles, joint compounds and adhesives. It poses a health risk to construction workers, repairmen, maintenance workers, restaurateurs, technical staff as well as the public near the historic building when it is damaged, crumbles, or is in a state of disrepair. The risk is even greater if the building is demolished, renovated, or remodeled [36].

Heavy Metal Impact (Lead and Tin)—Storage or other forms of lead transportation, lead coating, spraying of lead-containing paints or other lead-containing products during restoration activities, especially paint in restoration applications, removal of lead-containing coatings on fountain domes by sandblasting, burning, etc. Removal of lead-containing coatings on fountain domes using methods such as sandblasting, burning, etc., cutting lead-containing coatings by welding or oxygen welding, mechanical or thermal processing of lead, lead alloy or lead-containing coatings by mechanical methods such as sandblasting, roof coatings with lead-containing materials, painting glass in the restoration of historical buildings, tinning works can be shown as examples of activities where lead exposure may occur [37].

Falling Objects—Static problems in ancient monuments occur as a result of the detachments at the connection points of some elements such as chandeliers, paintings or wall panels. These ruptures cause the structural elements such as motifs or walls, etc., to separate from their places and cause injuries to the workers as a result of falling materials. For this reason, the suspension method is generally applied in such constructions. In addition, risks occur during the removal of materials from the building during restoration works. It is of great importance to plan the removal works in the application areas. Especially if the building is located in a built-up area; special precautions should be taken around the building such as traffic and pedestrian safety or restriction against the risk of material falling.

Falls From Height—The risk of falling from height, which is a consequence of working at height, is one of the important risk factors that can be encountered in restoration applications as in other construction activities. Most of the structures to be restored are “building” type structures. For this reason, working at height is one of the most important potential hazards. Restoration of historic buildings requires very detailed and long hours of cleaning, steam cleaning, sand blasting, artistic painting, engraving and similar works at height [34]. In historical aqueducts, bridges and various monumental structures from the past to the present, working at height is an important source of “danger” that should be foreseen. Another reason why this risk is high in restoration applications is the conditions of the structures that make working at height difficult. The equipment required for working at height can be more difficult to use in protected buildings. This is due to the static conditions of the buildings or the conditions that require intervention in their original state. In addition, it is risky to establish the lifelines on the unsound joint of the masonry building wall or another stable field without making sure that the load-bearing system of the historic building is strengthened.

Ergonomic Risk Factors—In restoration projects, due to the narrow areas that can be moved, the repair of the existing building in accordance with its original state with the least possible intervention, it may be necessary to exhibit a bad posture. In accordance with the principle of preserving the building in its original state, which prevails in restoration, ergonomic risk factors arising from the application work in accordance with the working conditions in and around the building should generally be evaluated within the scope of physical ergonomics and these factors are too many to be ignored. Some of these are inappropriate posture, material use, static posture, squeezing, excessive force, and standing for a long time.

3. Job Safety Analysis

Job safety analysis (JSA), which focuses on the interrelation among worker, task, tool and workplace environment, aims to define the hazards at each work item before their occurrence and produces solutions to completely eliminate the risks or to reduce the risks to acceptable levels [38]. The ideal is to sub-classify the work after defining uncontrollable hazards in order to completely eliminate these hazards or to reduce their risks to acceptable levels [39]. JSA might be adapted to almost all occupational groups. However, the branches of industry in which repeated processes are dominant are being better chosen in order to obtain economical and effective outputs [40]. The most important advantage of this method is the fact that the method is not entirely based on personal assessments and the hazard analysis is performed simultaneously with the work itself [41,42].

JSA, in this study, was performed based on findings coming from site observations conducted at three different restoration projects located in Türkiye. Three different JSA forms were created accordingly, since the processes of projects are largely different from each other due to their nature. The first column (operation) of the forms lists typical activities that workers engage in restoration. All possible hazards that workers could be exposed to during these operations are listed in the second column (hazard). Hazard-related information was primarily obtained from site observations and interviews with the key personnel of visited project sites. Finally, the third column (safety measure) on the forms suggested solutions for safety problems. Safety measures were mostly based on the information obtained from site visits to project sites. During these visits, safety managers and personnel were interviewed to understand proper safety measures. While some of these recommended measures were already in place, some did not exist due to budget restrictions. Also, observing the operations while they were being conducted and interviewing the workers who performed the job played key roles to come up with some of the safety measures. In addition, searching the safety literature to find best practices helped support the suggested measures.

The implementation of Job Safety Analysis (JSA) in restoration projects involves a systematic approach to ensure the safety of workers engaged in tasks within various project contexts. In a historic building restoration project, JSA begins with identifying specific tasks like masonry repair or window restoration, assessing associated hazards, evaluating risks, and developing safety controls and procedures, such as fall protection and lead abatement protocols. Controls may involve safety protocols, wildlife training, and appropriate personal protective equipment. Monument restoration projects require JSA for tasks like stone carving or structural repairs, addressing risks to the monument’s structural integrity, worker safety, and the preservation of historical structures. In all cases, JSA documents are crucial, outlining safety procedures and guidelines, ensuring that risks are systematically identified, assessed, and mitigated to protect workers and achieve the project’s restoration objectives, whether they are historical, ecological, or architectural in nature. Specific procedures and controls may vary based on project requirements and regulatory guidelines in effect during implementation. The job safety analysis applied in the study was also applied from this perspective. First, operations are identified, then potential hazards are identified, and appropriate safety measures are proposed.

4. Risk Analysis in Historical Buildings: Sample Restoration Projects

Similar to conventional construction projects, restoration/renovation/conservation projects require planning of all activities from the pre-construction to post-construction phase. When the literature is examined, although the studies supported by fieldwork are limited, we see that the potential hazards that may be involved in the restoration processes of historical buildings are categorically defined. In the scope of the study, three different restoration projects in Izmir are visited and on-site jobs observed, job safety analysis performed, related risks due to restoration works are detected, and a general flow chart for historic building restoration projects were established. The reason for choosing these three projects among different alternatives is that they cover all of the risk factors in the literature. Instead of selecting projects that are similar to each other and falling into repetition, we focused on the projects that were found to have different risks with the preliminary study and risk analyzes were carried out. In this way, practitioners were given the opportunity to see concretely all the risks that can be encountered within the scope of a restoration project, even if they do not encounter all of the risks listed in their projects. In addition, the fact that controls were carried out on behalf of the administration in all of the selected projects was decisive in terms of being present in the whole process.

The restoration process of historic buildings in Izmir involves complex and painstaking work. First, the history and documents of the historic building are analyzed. Then a restoration project is prepared, and approval is obtained from local conservation boards. Damage assessment is carried out and restoration workers repair or rebuild the damaged areas. Original materials and traditional techniques are preferred during restoration. Once completed, a plan for the preservation and maintenance of the building is created. The restoration process is carefully documented and can be used to sensitize the community to its history and cultural heritage. These projects can be long-term and costly but are of great importance for the preservation of historical and cultural heritage.

4.1. Clock Tower Restoration Project

Clock Tower, which is located in Konak Square and is the symbol of Izmir, was constructed in 1901 to celebrate the 25th anniversary of the reign of Sultan Abdulhamid II. It was commissioned by the council consisting of the Governor of İzmir Kamil Pasha from Cyprus, Said Pasha, the Navy Major General and Eşref Pasha, the Mayor. This building is 25 m high and has four floors and an octagonal plan. The platform is made of white marble and other structures are made of cut stone. The columns bear the theme of North Africa. The clock of the tower was presented by the German Emperor Wilhelm II. The outer facade of the Clock Tower is made of lozenge reliefs; and four clocks with the diameter of 75 cm. were added. The tower was damaged in the earthquake and the clock of the tower stopped at 02.04 when the earthquake occurred. Within two years the tower was repaired again, and the clock still works today [43].

During the restoration process, first of all, in order to increase the resistance of the building against earthquake effects, reinforcement solutions were applied without damaging the joint part of the interior, which cannot be seen from the facade. The 118-year-old Historical Clock Tower’s stones and marbles that were damaged or missing over the years were completed with materials and techniques suitable for its original state. In this context, firstly, a scaffolding in the form of a shell structure was created on the outside of the building so as not to create an additional load on the structure (Figure 3a). Afterwards, retrofitting works were carried out starting from the top of the tower (Figure 3b,c).

Stone surfaces were washed with non-pressurized water and marble parts were cleaned (Figure 4). Bronze parts and wrought iron were cleaned with micro precision sandblasting in a controlled manner. Protectors against the effects of rain, sun, etc., were applied on them. Falling or broken parts, bronze realms, fountains, broken stone fragments and falling stones with lily motifs were completed in accordance with their original state, and the water installation and lighting system of the building were renewed using luminaires without damaging the structure and in a way that cannot be seen from the facade.

4.2. Hacı Salih Pasha Fountain Restoration Project

The şadırvan (water-tank with a fountain), located at the square, was constructed in the 18th–19th centuries by Çeşmeli Ahmet Reşid. It is an octagonal structure made of marble. The dome is carried by eight marble columns. When the fountain was destroyed in time, it was repaired by Abdulhamid II in 1894. Having a unique architecture, Hacı Salih Pasha Fountain was built alone, not as a part of an architectural work like many other fountains. The second inscription for this restoration is located on the faucet mirror of the fountain. The octagonal structure, with round arches on each side supported by columns, is covered with a dome. The inner surface of the dome is plastered, and the outer surface is coated with lead. A domed mosque with two balconies, with floral shawl motifs on the curved capitals of the columns, floral motifs on the arch corners, six-armed star inside the medallion and flower motifs behind it is also depicted. The octagonal domed water reservoir is built of marble and each facade is crowned with an ornate hillock [44].

During the restoration works, the existing floor covering was preserved, and the surface was cleaned by using the sandblasting method. The detected broken or damaged parts were replaced in accordance with their original state in harmony with the structure. In addition, surface cleaning was carried out on all columns, small columns, wiping, lower capitals, upper capitals, plates and natural stone arches. Stolen fountains were also renewed within the scope of restoration works. The lead plated surface in the dome has been removed and refurbished (Figure 5). Finally, the work was completed by renewing the water installation.

4.3. Registered Building Restoration Project

The Registered Building on Block 1550 Parcel 15 has been used as a residence for many years, preserving its original plan, architecture and ornaments to a great extent. It is estimated to have been built in the late 19th–early 20th century. The plan, material properties and fixed ornamental elements of the building show that it was used as a residence for many years [45]. Built in a rectangular plan form, the building consists of two normal floors and a basement floor. The ownership of the building belongs to Izmir Metropolitan Municipality. The building combines Western European vernacular architecture and traditional Turkish architecture. All the windows of the building are rectangular, with jambs, partly with wrought iron railings, and a wooden bay window can be seen just above the main entrance.

Specific to the project, it is seen that the rooms on the ground floor are designed to serve public functions. The upper floor of the building has the same plan as the ground floor. Spatially, unlike the ground floor, it is seen in a more unified plan fiction. It is predicted that wet rooms were added to the masonry part of the historic building immediately after its construction. The additional part, which was originally a courtyard, was transformed into a two-story building by adding reinforced concrete floors. On the ground floor of this building, there is a kitchen and wet areas. The registered building, where restoration works were carried out in accordance with its original state, is located in Konak District, Pazaryeri Neighborhood.

The building, which is 235 m² in total, was removed and a reinforced concrete annex building was built to be used as a wet area. The roof of the main building was completely renewed in accordance with the original material structure. The basement floor was reinforced with injection. In addition, wooden window joinery, cage manufacturing and bay windows were renewed. In order to protect the cores on the ceilings, templates were taken, and micro injection was made on site. Interior doors, wooden flooring and metal shutters were preserved in their current state after the necessary processes (scraping, anti-rust, paint, etc.). Those of the ground floor carcasses that were intact and usable were preserved, and the missing ones were completed in accordance with the original (Figure 6).

5. Findings

JSA performed in this study generated three different forms that display potential hazards and their corresponding safety measures for each project. Results of JSA pertaining operations at different restoration projects can be seen in

Table 1. Job Safety Analysis of Clock Tower Restoration Project.

Operation	Hazard	Safety Measure
Identification of the project construction site and determination of its boundaries	Collisions and accidents in the area with narrow streets around the construction site, where traffic and people are dense	The working environment should be restricted
		Workers should be informed about the working environment
		A detailed site plan for the construction project should be created
		Cell phones should not be used within the construction site, especially in areas with traffic flow
		Temporary fencing should be installed
	Extremes in air temperature that harm employees	Working while preparing the shift list of employees’ periods should be taken into account
		Weather conditions should be monitored
Static evaluation of the structure and taking the samples	Material falling from unstable scaffolding during installation of reinforcement plates for retrofitting	The scaffolding should be covered with safety nets or panels to prevent falling materials
		Retrofitting works should not start until the scaffolding is used in a safe condition
	Fall due to unsafe act movement on scaffolding	Employees should be informed about working at height
		On-the-job training should be provided
		Weather conditions should be monitored
		Regular inspections should be conducted
Identification of areas that need to be reinforced	Fall of structural stones during suspension in preparation for retrofitting	Work environment boundaries should be defined
		Structural Assessment should be performed before the work
		Stone Stabilization should be planned
		Facades should be covered with safety nets or panels to prevent materials from falling
		Workers must use PPE (hard hat and steel-toed shoes)
	Splash of material used in plate assembly	The work area must be closed for the duration of the installation so that only the relevant persons are allowed to pass through
		PPE (mask, gloves, goggles) should be used during working hours
	Loss of balance and falls during repair or inspection	The area around the repaired area should be covered with a railing
		Safety net should be installed between the railing
		Lifelines must be created
		Workers should use parachute-type seat belts
Scaffolding erection to start site work	Falls during the erection of temporary scaffolding	Scaffolding should be erected by competent people
		Workers should use parachute-type seat belts
		If wooden scaffolding is installed, care should be taken to prepare a wooden scaffolding project in accordance with EN norms
Use of scaffolding for work at height	Scaffolding collapse	For heights up to 13.5 m, scaffolding made of wood with C16 strength and manufactured from wood conforming to standards should be used
Cleaning and repair of restored building elements	Eye damage due to dust in the environment	Wet work should be carried out if possible
		Dust in the environment should be filtered by vacuum
	Noise exposure	Necessary PPE should be provided to employees to avoid hearing problems
		Noise measurement should be completed
		Audiometer testing of employees should be carried out regularly
	Exposure to hazardous chemicals	Material safety data sheet (MSDS) of chemicals should be provided
		PPE that will prevent contact with chemicals should be used throughout the process
Washing of stone surfaces with non-pressurized water and cleaning of marble surfaces	Accidents due to slipping and falling during water cleaning	A cleaning instruction procedure should be prepared
		Non-slip shoes and hard hats should be used during work
	Injury due to falling marble material	Appropriate warning signs should be placed in the area to draw the attention of workers against material fall and injury

,

Table 2. Job Safety Analysis of Hacı Salih Pasha Fountain Restoration Project.

Operation	Hazard	Safety Measure
Removal of the dome the top of the structure	Fall from height during dismantling	Railings should be applied in accordance with the principle of not damaging the structure
		For the anchorage points of the lifelines, appropriate strength is required in accordance with the principle of protecting the structure. connection points should be identified
		With outriggers where anchoring is not possible mobile lifelines in accordance with EN norms should be preferred
		Instead of temporary edge protection systems that can be anchored to the ground, edge protection systems in accordance with EN 13374 standards with counterweights should be preferred
		Use technologies to reduce the necessity for work at heights, such as prefabrication, off-site assembly, mechanical assistance, or raised work platforms to minimize falling hazards
		Walking surfaces should be clear of debris, moisture, and other hazards that can cause slips and trips
	Fall of material during dome dismantling	Engineering assessment of the dome’s structure should be conduct
		Before dismantling, secure materials that are not being removed should be prevented them from falling inadvertently
		Procedures should be established for handling and lowering materials to the ground safely
		Hoisting equipment, cranes, or ropes should be used to lower materials under controlled conditions
Removal of lead surfaces on the dome	Loss of balance and falls during repair of lead surfaces	The repaired area should be covered with a railing and a safety net should be drawn between the railing
		Fall arrest systems (PFAS) with harnesses and lanyards should be used
		Walking surfaces should be clear of debris, moisture, and other hazards that can cause slips and trips
	Exposure to hazardous materials	The presence of hazardous materials such as asbestos, lead and tin in the building should be determined
		well-ventilated work areas should be Maintained
		If there are work items that will generate dust among the work items, dust measurement should be made measures must be taken
		Collective protection priorities and personal protection measures should be taken in closed work areas
		Waste should be controlled and managed by approved organizations

and

Table 3. Job Safety Analysis of Registered Building Restoration Project.

Operation	Hazard	Safety Measure
Cleaning of the construction site area before restoration applications	Biological risks arising from animal carcasses (such as bats, mice) and wood-damaging fungi and insect activity inside buildings	Continue working with a respirator when necessary
		Adequate ventilation in the working environment
		Biological risks should be identified in advance, personal protection, vaccination, measures such as spraying should be taken
	Loss of balance and falls while repairing or checking motifs	Site organization should be given importance against slipping and falling on the ground
	Fall of material during repair	Employees must use PPE (hard hat and steel-toed shoes)
		Unnecessary and not authentic elements should be eliminated from the structure
Template for the preservation of motifs on ceilings.	Loss of balance and falls during template retrieval	Walking surfaces should be clear of debris, moisture, and other hazards that can cause slips and trips
		guardrails, handrails, and safety barriers on elevated platforms, walkways, and scaffolding to provide additional protection against falls should be installed
		Non-slip shoes and hard hats should be used during work

, respectively. It is worth noting that in the risk analysis of the three restoration projects examined within the scope of the risk analysis, the risks identified within the scope of operations were handled in one project in order to avoid repetition in the analysis. All of the measures taken against the hazards foreseen in the job safety analysis are presented taking into account the legislation. The solution suggestions presented are applicable to projects with similar risk factors. The legislation examined in this context includes the following:

• Occupational Health and Safety Law No. 6331 [46],
• Regulation on Health and Safety Measures in Working with Asbestos [47],
• Regulation on the Prevention of Risks of Exposure to Biological Agents [48],
• Regulation on Manual Handling [49],
• Regulation on Occupational Health and Safety in Temporary or Fixed-Term Works [50],
• Regulation on Health and Safety Measures in Working with Chemical Substances [51],
• Regulation on the Use of Personal Protective Equipment in Workplaces [52],
• Health and Safety Signs Regulation [53],
• Regulation on the Vocational Training of Those to be Employed in Hazardous and Very Hazardous Class Jobs [54],
• Dust Control Regulation [55],
• Occupational Health and Safety Regulation in Construction Works [56],
• Regulation on the Protection of Employees from Noise-Related Risks [57],
• Regulation on the Procedures and Principles of Occupational Health and Safety Training of Employees [58],
• Occupational Health and Safety Risk Assessment Regulation [59],
• Regulation on Health and Safety Measures to be Taken in Workplace Buildings and Extensions [60].

6. Discussion

Today, historical buildings and monuments are considered as documents showing the architectural and urban structure, construction techniques and social conditions of the period in which they were built. In this respect, restoration projects are frequently applied to preserve and maintain the cultural heritage of societies. Although the issue has been discussed in detail in terms of architecture, the number of studies addressing the issue in terms of occupational health and safety is quite limited. This study aimed to fill this gap and raise awareness.

For protection from hazards, first of all, measures should be taken against the source of the hazard. These should be supported by measures that can be taken in terms of engineering and management. The technical measures to be taken are listed below.

In restoration projects, the definition and boundaries of the “construction site” is one of the main difficulties encountered due to its ambiguity and variability, and the fact that restoration is carried out in areas where the public and traffic flow is dense, tourism activities increase, and in the historical urban fabric with narrow street formation from the past [61]. Identification, sizing, and placing of temporary and permanent facilities within the confines of the construction site are all part of the layout design process. To maintain the safety of the working environment and effective and efficient operations, a proper site plan is essential. Planning the layout of the site has a big impact on how productive, expensive, and long a construction project is [62]: to define the boundaries of a construction site, conduct a property survey, review legal documents and zoning regulations, create a detailed site plan, mark boundary points with physical markers, install temporary fencing, inform stakeholders, implement safety measures, maintain records, regularly inspect and update markers, and conduct a final compliance inspection before project completion.

Structural damage can be a significant concern in restoration projects, particularly when working on older or historical buildings. Many restoration projects involve buildings or structures that have deteriorated over time due to factors like weathering, moisture, and wear and tear. This can result in structural damage, such as cracks, weakened foundations, and rot. In addition, past renovations or modifications to the building may not have been completed correctly or could have used outdated construction methods, potentially causing structural issues that need to be addressed during restoration. Structural damage can also arise due to deterioration, foundation issues, water damage, pest infestations, fire damage, or environmental factors [63,64]. To address these concerns, thorough structural assessments, expert guidance, and a well-designed restoration plan are essential. Monitoring the restoration process closely ensures that structural repairs are executed correctly while preserving the historical and architectural significance of the building or structure.

Scaffolding installation is a critical component of many restoration projects, especially when working on buildings or structures with height and architectural complexity. Scaffolding installation in restoration projects involves careful planning, compliance with regulations, and following specific steps [65,66]. This includes assessing the project needs, selecting the right type of scaffolding, designing for safety and stability, site preparation, assembly, safety measures, regular inspections, controlled access, maintenance, proper dismantling, documentation, and worker training. Scaffolding enables safe access to work on complex or elevated areas in restoration projects while ensuring worker safety and regulatory compliance.

Falls from height are a significant safety concern in restoration projects, especially when working on elevated structures. Preventing falls from height in restoration projects is vital due to the inherent risks associated with elevated work. Key factors contributing to these risks include working at heights, uneven surfaces, limited access, and adverse weather conditions [67]. To address this, precautions include implementing fall protection systems, ensuring scaffolding and platforms are secure, promoting ladder safety, using proper PPE, conducting regular inspections, monitoring weather conditions, controlling access, providing training, and fostering a safety-focused culture. These measures aim to safeguard workers’ well-being and the success of restoration projects.

Another problem encountered in restoration construction work is the difficulties in the field of ergonomics. The first of the causes of these difficulties is inappropriate posture, which consists of prolonged and repetitive sitting, kneeling, bending, working overhead with the hand or arm, or standing in a fixed posture [68]. In restoration construction work, ergonomic challenges often arise due to factors like aging infrastructure, limited space, historical preservation requirements, accessibility issues, inadequate tools, safety concerns, and a lack of awareness [69]. Addressing these challenges requires careful planning, proper equipment selection, worker training, and process adaptations to prioritize worker health and safety while preserving the project’s goals.

Biological risks arising from animal carcasses (such as bats, mice) and pests such as insects that damage wood are another challenge of the working environment in restoration activities. Older structures may have water damage or poor ventilation, leading to the growth of mold and mildew. Workers can be exposed to harmful spores, which can cause respiratory problems and allergies [70]. Older structures are more susceptible to pest infestations, such as rodents and insects. Workers may encounter pests and their waste, potentially leading to the spread of diseases. In some cases, restoration sites may have been abandoned or neglected, leading to the accumulation of organic matter and the potential for bacterial or viral contamination, which can pose health risks to workers. To address biological risks in restoration activities, take precautions such as conducting site assessments, providing workers with proper protective gear, offering training on hazard recognition and PPE use, implementing safe practices, complying with regulations, maintaining good hygiene, monitoring for hazards, and establishing emergency response protocols.

Since many of the buildings to be protected are located in built-up areas, environmental security projects should be designed as a priority at the beginning of the project. In addition, precautions (safety nets, area delimitations, etc.) should be taken against situations such as some parts of the restored building breaking off, breaking, and falling over. That the area around the repaired area should be covered with a railing and a net should be drawn between the railing also suggested that the areas where work is carried out should be covered with railings and a net or wire mesh should be drawn between the railings [25].

Due to years of exposure to heavy metals such as lead and tin, restoration workers may suffer from lead poisoning and serious diseases in the long term. For this reason, PPE (mask, gloves, goggles) should be used during working hours and respirators should be worn in areas where necessary [71,72]. To safeguard restoration workers from long-term health risks linked to heavy metal exposure, such as lead and tin, it is imperative to enforce the use of proper personal protective equipment (PPE), provide thorough training in handling these materials safely, conduct regular monitoring of exposure levels, maintain well-ventilated work areas, comply with relevant regulations, and offer access to medical surveillance and periodic health check-ups for early detection and management of potential health issues.

The health and safety measures taken in the construction site in restoration projects can be specified as nets, cover systems, area cleaning and delimitation, etc., to prevent material falls. Since the definition of the construction site boundary varies considerably, measures outside the construction site should also be evaluated according to the original condition of the application area. In 2020, Uzun et al. suggested that measures be taken in terms of heavy traffic flow and accessibility and time planning should be taken into account when planning restoration works on a narrow street [5]. In addition, they emphasized that other administrative and practical activities such as determining the contractor in the project, duration planning of the work, material selection, etc., should be carried out in accordance with the risk control hierarchy by making use of the analyzes carried out while handling the project.

Implementing practical health and safety measures in construction site restoration projects is paramount to safeguarding workers and ensuring the successful preservation of historical structures. Begin with a comprehensive risk assessment tailored to the unique challenges of the project, taking into account historical materials, structural conditions, and specific hazards associated with the restoration process. Provide thorough training for workers, emphasizing the handling of delicate materials and the use of specialized equipment. Ensure the availability and proper use of personal protective equipment (PPE), adjusting requirements as needed. Develop site-specific safety plans addressing factors like limited access and specialized equipment use. Prioritize fall prevention measures, emergency response planning, and regular site inspections to promptly address safety concerns. Pay particular attention to scaffolding safety, tool and equipment maintenance, and proper waste management. Implement health monitoring programs to track potential health issues arising from exposure to hazardous materials. Engage with the local community, communicate project details, and collaborate with historic preservation experts to incorporate their insights into safety planning. Regularly conduct training refreshers, and commit to ongoing communication, training, and continuous improvement as essential components of a successful safety strategy in restoration projects. All those precautions require different tools, equipment and knowledge level for designers, practitioners, and restoration professionals. For instance, Godinho et al. (2020) suggests BIM as a tool and fundamental commencement for heritage management. Due to their peculiar geometric characteristics, integration of BIM with the geometric representation of historic buildings is a starting point [73].

In addition, the effective implementation of all these safety measures requires teamwork. Occupational safety measures should be implemented through a collaborative effort involving employers, employees, government agencies, safety committees, safety professionals, trade unions, suppliers, professional organizations, and third-party auditors. The employer is responsible for the general responsibility and liability for occupational health and safety issues. The employer is obliged to work together with the occupational safety specialist and workplace physician to guide him in this respect. However, this does not eliminate the responsibility of the employer. If there is a sub-employer in practice, the main employer is responsible together with the sub-employer. What is expected from the worker in the process is full adaptation to the process and compliance with occupational safety practices. Labor inspectors affiliated to the Ministry of Labor and Social Security carry out the inspection on behalf of the public. However, public institutions have the right to inspect and instruct the employer in terms of occupational safety since they have the status of business owner in projects commissioned through tender procedure [46,74].

Each group has its role and responsibilities in ensuring workplace safety, and cooperation is crucial for creating a safe work environment.

Council Directive 92/57/EEC outlines safety and health requirements for temporary or mobile construction sites in the European Union. It emphasizes integrated safety planning, risk assessment, cooperation among stakeholders, safety and health plans, training, and compliance with safety standards to protect construction workers’ well-being. It is very important that this directive is also taken into account and implemented [75].

7. Conclusions

Occupational safety in restoration projects of historic buildings is crucial for preserving cultural heritage, safeguarding priceless artifacts, ensuring worker well-being, and maintaining the integrity of these significant structures. Therefore, projects for the restoration of historical buildings are widely carried out at the global level.

Moreover, restoration projects of immovable cultural assets are projects with different dynamics than standard construction projects that need to be carried out in line with the conservation phenomenon. Occupational safety in restoration projects of historic buildings is of paramount importance due to the unique challenges and considerations associated with working on such structures. If these risks cannot be managed systematically in restoration projects, occupational accidents are inevitable.

In this study, occupational health and safety in historical buildings, the measures to be taken, and the applicability of the measures to be taken through risk analysis were investigated. The literature review showed that there is a very limited number of studies that deal with occupational health and safety during the restoration of a historical building. By using the job safety analysis method with the research and examinations, the restoration process of three historical buildings, which contain different hazards from each other, has been examined in terms of occupational health and safety. It is worth noting that some of the measures presented in the study are actually known within the scope of general occupational safety practices in the construction sector. However, one of the most prominent benefits of this study is to bring together and summarize the measures that should be taken into account when it comes to occupational safety in the restoration process of historical buildings and that are not prominent in a standard construction work (such as biological risk factors).

In summary, occupational safety in the restoration of historic buildings is vital for preserving cultural heritage, protecting valuable artifacts, ensuring worker well-being, and maintaining the integrity of these significant structures. It requires a unique blend of traditional construction safety practices and specialized knowledge of historical preservation techniques to ensure both the safety of workers and the preservation of our historical legacy.