Functional Continuity in Adaptive Reuse of Historic Buildings: Evaluating a Studio Experience

View current table in a new window

Tables index

Veiw figure View Table

View next table

Therefore, Ali Pasa Han, with considerable historic and cultural background, was given as a task to the students of ITU Interior Architecture III Project Studio during the 2014-2015 Fall Semester.

Ali Pasa Han is one of the most typical examples of Ottoman City Hans ^[1] (Figure 1). Han can be defined as a building typology developed by the Early Ottomans. While some hans served as a roadside inns where travelers could rest and recover from the day's journey, some were used as a place for commercial production and exchange of various goods ^[2]. They were usually two storey buildings characterized by identical spaces called cells surrounding a courtyard. Gülenaz ^[3] classifies hans in two groups as commerce hans and accommodation hans. The ground floors of accommodation hans were reserved for depos(storage) and the first floors were used for accommodation. On the other hand in commerce hans while the ground floor was used for stores and depos, the first floor was used for ateliers and offices.

Figure 1. The Ground Floor Plan of Ali Pasa Han [4]

Download as

Veiw figure View Figure

Figure 2. The Section-Elevation of Ali Pasa Han [4]

Download as

Veiw figure View Figure

Ali Pasa Han is located in Eminönü on the Golden Horn and it is in a predominantly commercial zone within which various products can be found. Typical of Ottoman Hans, it is built of stone with brick horizontal stripes. It is a two storey han which has a rectangular courtyard in the middle surrounded by arcades (Figure 2). The arcades create access to cells. While each cell is of private property, the courtyard is public.

After evaluating the data gathered from the thesis of Aksu ^[1], distribution of the cells according to the activities they are used for were defined in Figure 3. According to the situation in 1999, only 12 cells out of 58 cells are used for commercial activities. Half of these commercial units sell traditional products such as hand made blankets and candies. Among 10 cells that are used for production, all of them belong to old artisan groups like coppersmiths, knife makers, steelyard makers, candy makers, harness and saddle makers. But 24 cells located upstairs are empty and 8 cells are used as depos. Most probably all these empty units were also used both for production and commercial activity during the initial phases of the building. While the cells facing the street attracted passerbys, the rest of the building functioned in relation to the spatial organization of the building. When we evaluated the change in the present situation of the Han, we observed that only the courtyard is now used as an open-air temporary theater. In general the distribution of activities has remained as it was in 1999.

Figure 3. The Distribution of Activities in The Cells of Ali Pasa Han

Download as

Veiw figure View Figure

2. Purpose and Methodology

Basic steps of adaptive reuse can be identified as analysis, determining compatible use, developing project proposal and realization. This study includes only the first three steps as the last step requires specific expertise and knowledge ^[5].

The purpose of this study is to create adaptive reuse proposals for a historic building of commerce by focusing on “functional continuity”. In other words, the students were asked to consider the importance of cultural interaction in a commercial building with significant historic background and they were expected to create proposals by evaluating its spatial potentials in functional continuity.

In the first phase of the study, the course program will be organized in different steps according to the course catalog form and 14 weeks program. At the end of every step there will be a jury to evaluate the different phases of the proposals. Every step will have its own priorities and criteria for jury evaluation.

3. Determining the Basic Steps of the Course Program

The students were asked to develop a holistic reuse proposal for the building in order to create cultural interaction. As the student group was an international one with several Erasmus students, the theme of cultural interaction also had a practical grounding. All the activities and functions were to be defined by the students. Table 2 shows the course program in relation the studio process. As shown in Table 2, at the first step they were asked to analyze the building by using a framework defined by the tutors. Then they were to create a scenario in relation to the context and define all the activities and their interrelations. After creating the building program, they started to develop their proposals.

Table 2. Summarized Course Program of ITU Interior Architecture Project III, 2014-2015 Fall Semester

Download as

View current table in a new window

Tables index

Veiw figure View Table

View previous table

View next table

As discussed before, interior architecture is concerned with existing buildings. Therefore analysis is essential for all activities concerned with interior architecture. On the other hand, especially for buildings with cultural significance the extent, purpose and functional change is extremely important. Therefore the basic steps of the course and jury sessions are defined as follows:

• Step I: Analyzing the building to understand spatial potentials

• Step II: Determining a compatible use and creating a scenario

• Step III: Developing the project proposal

The results were discussed and evaluated by a jury, which was formed of specialists with different professional backgrounds related to the steps above. Therefore, the composition of the jury changed according to the priorities of the process. At the first jury, while discussing the results of analysis and determining architectural potentials, the leader of the project team who has prepared the restoration project for Ali Pasa Han, was invited to the jury. At the second jury, while determining a compatible use, a specialist with considerable experience about reuse was asked to evaluate proposals. The third jury was enriched by the contributions of architects from practice. All the findings of the process will be discussed according to the basic steps defined above.

3.1. Step I: Analysis for Understanding Spatial Potentials

There are many different methods in analyzing architecture with different concerns.

However, priority of the analysis in adaptive reuse is to understand architectural and spatial potentials embedded within historic buildings and their components. These potentials help us understand the cultural significance of a building and define compatible use.

During the analysis for understanding spatial potentials, students were asked to analyze historic buildings through the criteria defined below ^[6]:

• Contextual Ties

• Tectonic Order and Material

• Geometric Relations

• Spatial Organization

• Spatial Circulation.

3.1.1. Contextual Ties

In order to understand a building, it is necessary to grasp the exterior forces that shape it. While analyzing the relationship between the building and the urban environment that surround it, it is necessary to look at the urban spatial envelope, predominant paths, density, important buildings, structures and landmarks around the building.

According to the evaluations in the studio about the present situation of Ali Paşa Han, it is observed that the building is within a very dense urban infrastructure and this can be regarded as one of the most important potentials of the building. Although the building faces the shoreline of the Golden Horn on the Northern side, the main entrance of the building is from a narrow street at the South West. But the entrances of all the ground floor cells both on the shoreline and at the back are directly from the street. The density on the shoreline side is considerably high. As the cells on the shoreline are not connected to the courtyard, there is no passage between the streets through the building. So, the building has no direct relation with the main street except the cells facing the street.

3.1.2. Tectonic Order

Tectonic order arises from the relationship between architectural elements that come together with the principles of gravity. Gravity helps to define a hierarchy, which is vital for the consistency of the building. This hierarchy can be easily read in section starting from top towards the ground by looking at architectural components, elements and the ground. In Ali Pasa Han, the hierarchical relations between cross vaults, barrel vaults and thick loadbearing walls can be observed at both levels. The repetition of the identical units or cells limit interventions on loadbearing walls as the walls also support the original vaults. The courtyard composed of galleries with barrel vaults face the courtyard by Ottoman pointed arches.

3.1.3. Geometric Relations

Resolving geometries in a historic building is one of the most important steps of architectural analysis because all buildings are defined by the togetherness of basic or complex geometric forms and these geometries create spatial forces according to their articulation. While analyzing Ali Pasa Han by focusing on the geometry of building mass and void, it can be seen that the building fills the urban space defined in linear organization and it has a rectangular void or courtyard that has direct relation to the contour of the building. The togetherness of the cells defines an overall geometric grid and spatial character.

3.1.4. Spatial Organization

In a building program spaces with different intentions and priorities come together. Usually in historic buildings different spatial organization types are used together in order to define spatial hierarchy. In the ground floor plan of Ali Pasa Han, while the cells around the courtyard are articulated with centralized organization, spaces along the entrance axis and service corridor are arranged in linear organization. The ground floor cells through the streets at both sides of the building are also arranged with linear organization. The first floor resembles the ground floor in terms of spatial organization except the courtyard. Although the first floor cells are also arranged around the central courtyard they come together in linear organisation because of the void in the middle.

3.1.5. Spatial Circulation

Spatial circulation is the way or path that is predefined by the architect in order to create hierarchical access for all spatial components in a building. In order to understand spatial circulation it is essential to consider the starting point, the layout and the architectural definition of the path. In Ali Paşa Han, the starting point is the archway on the narrow street at the southern part of the building. This archway leads to the main circulation system, which is articulated around the courtyard. The cells are attached to the rectangular circulation system in both floors. Access to the first floor is provided by stairs, which are also part of the main circulation system. The architectural definition of the path is characterized by barrel vaults and galleries facing the courtyard

3.2. Step II: Determining a Compatible Use and Fuctional Continuity

Determining a compatible use necessitate the functional evaluation of the building’s present situation and the effects of all previous interventions. According to the Burra Charter ^[7], fabric, uses, associations or meanings of different periods, or different aspects of cultural significance should be respected. So, the present situation of a historic building can be regarded as a multilayered structure of evidence. Therefore, at the step of “Determining a compatible use and functional continuity” the evaluation criteria was defined as follows:

• Evaluating the present functional properties

• Determining a compatible use.

3.2.1. Evaluating The Present Functional Properties

After analyzing the building, the students were asked to evaluate the existing situation of the building in order to understand the complications related to the activities and functions that take place in it. Main problems related to present functional properties of the building were defined as follows:

• Functional discontinuity

• Detachment of spatial and functional organization

• Misuse of innate functional properties.

After evaluations in the studio, it was observed that the functions of cells were mostly determined by their roles in spatial organization. While the ground floor cells around the courtyard are mostly used for production, the cells connected to the streets are used as retail units. On the other hand most of the cells on the first floor are empty and the upper level is devoid of activity. All ground floor units are subject to interventions that have different objectives and priorities. A historic building situated at the commercial core of Istanbul is used for different purposes and activities that do not have any practical or conceptual relation to each other. The most important reason for this spatial and functional discontinuity is the fact that the cells belong to all different individuals and the way they utilize the space is not organized at all. As a result each cell or unit is modified according to its owners’ expectations and needs thus the building suffers from the lack of overall operational organization.

The initial use of a building reflects its overall intention and its contextual role. The spatial organization is mostly determined by the activities that are predefined in the building program. But just like the example of Ali Pasa Han, in time these activities change according to social, economic and cultural factors, which usually have certain contextual ties. Due to the effect of these changes, integrity of the building program starts to be dispersed and parts of the building start to be used for different activities. This inevitable fact leads to a certain detachment between the functional and spatial organization of the building.

Functional organization is about the relationship of activities that take place in a building. Just like spatial organization every space has a functional role in the overall functional organization of the building. But there are some innate functional properties that are hard to change. For example a building’s functional organization often hinges on delineating service and served spaces. According to Jenkins ^[8], regardless of scale or segregation degree, delineating and balancing service and served zones remain vital in the life of a building. The degradation between public and private is also another functional property that is hard to change if the fabric of the building is not changed. Today on the ground floor of Ali Paşa Han we can observe that the initially public galleries that surround the courtyard are closed and isolated from the central courtyard and have lost their public character. As these types of interventions ruin the innate functional and spatial character of the building, they need to be removed. Innate functional properties need to be evaluated in order to define the new functions that will take place in a building.

3.2.2. Determining a Compatible Use

The Burra Charter ^[7], defines the aim of conservation as retaining the cultural significance of a place. According to the Charter, cultural significance is embodied in the place itself, its fabric, setting, use, associations, meanings, records, related places and related objects.

As the functional organization of a building reflects its role and intention, it is a part of its cultural significance. On the other hand it is generally very difficult to preserve all the initial functions of a building. At this point, it becomes important to define a compatible use for historic buildings which is defined as a use that respects the cultural significance of a place ^[7], Such a use involves no, or minimal, impact on cultural significance. Changes which may reduce cultural significance should be reversible and be reversed when circumstances permit. Therefore, while determining a compatible use for Ali Pasa Han, the students were asked to proceed in 3 steps:

• Proposing a conceptual model or diagram

• Creating a scenario

• Defining the building program.

At the first step of determining a compatible use, students were encouraged to define the role of the building within the context of Eminönü. After the analysis students became aware of the building’s different phases, changing functional character and potentials. It was also important to develop an idea that could enhance new ways of functional continuity. Even if the cells belong to individuals, public role of the building was to be underlined. Therefore, the new use needed to consider:

• The initial uses and spatial potentials that were discussed during analysis

• The present situation and complications

• The contribution of the building to new ways of functional continuity.

Figure 4. The Conceptual Diagram of A Student Work [9]

Download as

Veiw figure View Figure

Figure 4 shows the conceptual model developed by one of the students. The intention of the student was to create cultural interaction by creating a center for the exhibition, degustation and sale of various local Anatolian wines through events such as festivals and thematic gatherings. The bubble diagram can be regarded as an interpretation of the main theme and its relation to history, context and activities.

After defining the intention of the proposal, the students tried to develop a scenario to explain their projections for the course of actions that are supposed to be a part of spatial experience. According to Ertugrul ^[10], when architectural scenario illustrates the architectural space, it should be narrative and supplementary to the visual material as an additional medium for representation. So the scenario can be regarded as a tool to narrate the “story’ of the building, which may not be expressed in visual terms. Figure 5 shows the representation at one of the student’s scenario. The student has tried to define the activities and their spatial complements by using a section. Her aim was to design a center called “Lab” to create cultural interaction through music and sound which can be regarded as one of the most important components of culture.

Figure 5. The Conceptual Representation of The Scenario [11]

Download as

Veiw figure View Figure

Figure 6. The Building Program and Its Relation to The Building [11]

Download as

Veiw figure View Figure

During the last phase of defining compatible use, the students created their building programs according to their scenarios. After defining the activities and their spatial requirements they started to work on different configurations of the program by discussing alternatives on plans. Figure 6 shows the program of proposal developed for the same project Lab. The student has proposed use of both levels for exhibition. While commercial activity was concentrated around the courtyard on the ground floor, experimental studies were organized on the first floor. Exhibition spaces were distributed to the whole building creating spatial continuity and increase the attraction of the first floor.

3.3. Step III: Developing the Proposals and Project Results

At the third step of the study, which has been defined as “developing the proposals and project results” studio outcomes were evaluated in terms of “functional continuity”. Every intervention on historic buildings needs to consider both adaptation and conservation. While conservation focuses on the continuity of the building, adaptation aims to increase its functionality. Therefore “functional continuity” cannot be discussed independent from adaptation and conservation. Because the term functional continuity does not only deal with the relationship of current activities in a building but it also involves the relationship of these activities with the building’s previous phases and context.

After creating the building program students started to develop their proposals. Consciousness about the generally accepted principles of conservation was regarded as an important issue so at this step the students needed to define the extent of intervention by taking into account some of the basic principles described by the tutors. These principles can be regarded as an interpretation of the basic conservation principles defined by the Venice Charter for interventions in interiors:

• Authenticity: respect for the valid contributions of all periods

• Reversibility: ability to undo all interventions

• Differentiation: difference between old and new layers.

According to the Venice Charter ^[12], the present situation of a historic structure even destroyed or damaged represents “a state of understanding”. Due to the requirement of the preservation of as much of the original material as possible, any intervention should be kept minimum ^[13]. Conservation theory has also placed value on “reversibility” which is defined as the ability to undo repairs that later generations regard as substandard or incorrect ^[14]. For interiors reversible interventions are even more important as they are changed more often according to changing human needs. Differentiation between the new intervention and the existing building helps to maintain reversibility since additions are often structured as independent bodies and they are built of different materials and techniques with a new design language ^[15].

Other than the principles of conservation, as mentioned before, students were also asked to take into account the essentials about adaptation. According to Forsyth ^[16] too much focus on conservation can cause loss of vitality and historic cities can become heritage museums. Conservation has as much to do with breathing new life into old buildings as it has with repair. Cities and all their components including buildings and their interiors are living structures. If they are abandoned without a use, they become frozen in time. Reuse is the way to make them breathe and make them a part of our lives.

Adaptation to new requirements in public and commercial interiors can be discussed in many ways that can be summarized as functional requirements, human comfort and health requirements, aesthetic requirements and expression of brand identity ^[15].

Starting from the eight week of the semester, students worked on developing their proposals by considering both principles of conservation and adaptation requirements. At the end of the third step at fourteenth week of the course, the jury made its evaluations by focusing on the theme of “functional continuity” and proposals were classified according to their main approaches. The most important advantages and disadvantages of every different type of approach are identified in Table 3.

Table 3. The Evaluation of the Studio Experience in Terms of Functional Continuity

Download as

View current table in a new window

Tables index

Veiw figure View Table

View previous table

The results, which are summarized in Table 3, will be discussed in detail with examples from the studio.

3.3.1. Result I: Central Point

The most important challenges of the approach to central point were to utilize the courtyard as a place for cultural interaction and enhance its innate role as the central component of spatial organization. Figure 7 shows the proposal of one of the Erasmus students whose intention was to use the courtyard for traditional and contemporary shadow art shows and exhibitions. Therefore she needed to define a structure to embrace all the technical equipment without detracting from the spatial character of the courtyard. The student proposed open exhibition spaces in the cells opening to the main street and created visual relation with the courtyard. On the ground floor there was a mixture of ateliers and sales units practically in relation to each other. The first floor was mostly used for ateliers, workshop spaces and cafeteria. The building program was developed in order to create a center to exhibit, design, produce and interpret ottoman patterns on different platforms and products. The interiors were also embellished by surfaces and products produced in the ateliers (Figure 8).

As it can be seen from the student project, the approach that emphasizes the courtyard as central point highlights the spatial potential of the courtyard but it diminishes the functional continuity between ground floor cells and the courtyard because of the specific use defined for the courtyard. On the other hand the attraction of the courtyard creates ta strong spatial hierarchy and enriches spatial experience.

Figure 7. Student Proposal, Section-Elevation From Courtyard [17]

Download as

Veiw figure View Figure

Figure 8. Student Proposal, Detail of a Cell [17]

Download as

Veiw figure View Figure

3.3.2. Result II: Interpretation of The Circulation System-New Stairs, New Paths

Figure 9. Student Proposal, Section-Elevation [18]

Download as

Veiw figure View Figure

Figure 10. Student proposal, ground floor plan [18]

Download as

Veiw figure View Figure

Some of the students proposed to strengthen the relationship between the two levels by adding new stairs to the courtyard. Figure 9 and Figure 10 shows the proposal of one of these students that used the stairway as an element to connect the flow from the street facing the Golden Horn and the narrow street at the backside and direct them both to the upper floor. She proposed a center within which coppersmiths and carpenters could work and exhibit their products. Her aim was to increase the importance and accessibility to the upper level through stairs. While the ground floor was used for ateliers and shops, the first floor was used for exhibition.

3.3.3. Result III: Overall Conceptual Organization

All student proposals were developed by organizing spaces and activities within a holistic conceptual approach. Some of the projects, however, this conceptual organization was used a tool to maintain functional continuity. In a student proposal that was developed according to this approach, the visualization of sound was used as a tool to create functional ties between the cells (Figure 11). The aim of the student was to create a center within which disciplines such as visual arts, architecture, performance, computer programming and music could work together to enhance activities related to experimental studies about music and sound.

Figure 11. Student Proposal, Ground Floor Plan, Perspective From The Entrance and A Cell [11]

Download as

Veiw figure View Figure

3.3.4. Result IV: Relationship of Activities

Figure 12. Student Proposal, Ground Floor Plan [9]

Download as

Veiw figure View Figure

Relationship of activities can be regarded as one of the most efficient tools in order to maintain functional continuity. One of the students that used this approach has studied the history of the production of Anatolian wines and transferred his findings to the spatial organisation of the building. Spatial activities were linked to each other in relation to the chronology of the production of different types of Anatolian wines (Figure 12).

3.3.5. Result 5: Emphasizing Urban Continuity

Especially in city centres the ground floors of historic buildings have great potential as continuations of open-air public spaces. When accompanied by a socially useful purpose, this great potential can be regarded as an attraction to increase the accessibility and reveal the cultural significance of the whole building ^[19]. In one of the projects that was developed with this approach, ground floor cells facing the street was used as open-air meeting and multi-purpose working spaces (Figure 13). Therefore the penetrability of the building shell was greatly increased and contextual relations were strengthened. The spatial and functional continuity between the street and cells was also evaluated as an approach that enriched the activities on the street. On the other hand the individuality of the building was lessened because of the ambiguity of spatial borders between the street and the cells.

Figure 13. Student Proposal, Ground Floor Plan and Section [20]

Download as

Veiw figure View Figure