Qajar religious schools are all located in the old grand bazaar of Tehran. Due to the high economic value of the land, most of these buildings have been destroyed and some shops or stores have been built in their places. Also, in some of the remaining schools, only spaces with less important uses have been demolished and some shops have been built in their place. About these schools, the biggest concern is their unprincipled and unresearched restoration, which has damaged their physical values. For example, they were restored regardless of their original materials or main ornamentations, making the restored building to be not in harmony with the original one and thereby damaging the authenticity of the building. Also, the most important semantic values in these buildings are the active presence of people to do religious affairs or teach religious lessons to students. Due to the ban on the use of schools by their owners, the intangible and semantic values of education and worship have diminished.
Literature review
Various studies have been conducted in the field of Qajar religious schools in Tehran, including the history of education [1,2,3,4]; space analysis [5,6,7]; Architectural Typology [5, 8, 9], and spatial evolution [10,11,12,13,14].
The study by Taher-Toloudel et al. is the only research on the value conservation and revitalization of these schools. The results of their research have indicated that it is not adequate to pay attention only to the physical and tangible aspects of the building for the value conservation of the schools and it is required to consider the non-physical and intangible aspects of the building [15]. In another study, they have also identified seven factors effective in the value revitalization of these buildings based on interviews with experts. These seven factors include climatic architecture (climatic factor), resilient architecture (resilient factor), spiritual architecture (spiritual factor), environmental aesthetics (aesthetic factor), educational architecture (educational factor), structural architecture (structural factor), and site visiting (tourism factor) [16]. Moreover, according to the research method used, they have identified only the factors effective in the value revitalization and their constituent variables and the relationships between factors and variables have remained unknown. Therefore, the present study aims to investigate the relationships between factors and variables. The main research hypothesis is based on the fact that architectural phenomena, through value conservation, have the most significant effect on the value revitalization of Qajar religious schools in Tehran.
This article is the third part of an investigation into the value revitalization of Qajar religious schools in Tehran.
Research variables
In the present study, the independent variable is architectural phenomena, the mediator variable is value conservation, and the dependent variable is value revitalization (Fig. 1).
Independent and mediator variables were extracted using the study results by [15] and dependent variables based on the results of the study by [16].
Independent variables: architectural phenomena
Architectural phenomena are classified into five classes of form, function, concept, technology, and integrity based on literature review and interviews with 25 architectural experts [15].
Form: The form refers to the shape and arrangement of components and the visible aspect of the architectural work [17]. It is the perceivable character, and identity of objects, and objects are known and distinguished with it. While the architectural form is a visible image of the material shaping it. Thus, it has components, proportions, and size. It includes and conveys the concept of human and the characteristics of the environment, and is a function of how humans perceive the world [18]. The form is the most main architectural factor and must be coordinated with factors such as value system, cultures, environmental, functional, as well as sustainable conditions [19]. The form refers to the appearance and three-dimensional shape of these schools.
Function: In the present study, function refers to the use provided for the users by the building. The functions of religious schools are including educational, residential, and devotional uses [15].
Concept: In architecture, a concept is actually an idea, a source of inspiration, or a motivational thought according to which actions are taken [20]. In fact, it is a relationship between subjectivity and objectivity, that is the architect uses the concept to represent his mental design by designing a building in reality [21]. The architecture was considered a symbolic language that could present spiritual concepts with patterns understandable to human beings. In religious schools, since architecture aims to capture the soul and intellect, geometry has become a tool for the Iranian architects to develop the forms of plants and animals that were inherently sacred [22]. Thhie concept is to use ideas in school architecture based on spiritual and moral subjects.
Technology: Technology is a set of construction skills. Buildings, from early shelters to modern complex buildings, have been associated with the constant presence of a type of construction system for resistance to gravitational forces, winds, earthquakes, etc., throughout the periods of technological evolution [23, 24]. Throughout history, humans have always had to build strong and safe buildings to protect themselves against destructive factors and forces and to identify and control the forces on the architectural structure in a reliable way [25]. The structural technology used in these schools is the traditional structures of Iran, namely arches and domes. This type of structure, while being static and reliable, is beautiful and is not separate from architecture.
Integrity: It refers to architectural variables that cannot be placed in a single form, function, concept, and technology category. These variables are multidimensional, such as cultural, historical, and aesthetic values.
Mediator variables: value conservation
From the contemporary view towards conservation, the major issue is to conserve values. It is no longer a product and is itself a conservation process [26]. This process is called value-based conservation. The measurement of values plays a key role in all measures related to architectural heritage as Feilden [27] states, the first step in the conservation process is to set a goal and then prioritize the existing values in the building to understand and convey the message of the work. In general, conservation activities take place when the object or location is valuable, and therefore making decisions on how to treat and intervene in the work follows this value [28].
The ICOMOS New Zealand Charter is one of the charters in the field of value-based conservation. In this charter, conservation aims to preserve the values of the architectural heritage [29]. Conservation of architectural heritage values can be observed in the three main aspects including the conservation of tangible values (physical conservation), conservation of intangible values (semantic conservation), and conservation of semi-tangible values (compound conservation), to which different priorities are allocated in different societies, according to their cultural and environmental contexts [30, 31].
Dependent variables: value revitalization
Each architectural work has a special value and a special cultural-historical place in its society according to its time, location, architectural technique, common models at the time of construction, use, and form [32]. The value changes over time as the building remains unused, as well as due to natural disasters and human hazards, the architectural work will be exposed to deterioration and destruction and this raises the need to conserve it [30, 31]. In most countries, one of the measures taken to conserve historical monuments is to revive them through the revitalization of existing values in the building [33, 34]. Factors affecting the value revitalization of Qajar religious schools in Tehran, based on interviews with experts and using the Delphi method, and Q factor analysis, include seven factors (climatic, resilience, spiritual, aesthetic, educational, structural, and tourism) [16].