FRACTAL BASED GENERATIVE DESIGN FOR HARMONY BETWEEN OLD AND NEW

 

Prof. Dr. Gülen ÇAGDAŞ                                                                                               Head of Architectural Design Division, Faculty of Architecture,                                                                                                                                                              Coordinator of Architectural Computing Master Program, Institute of Informatics,  Istanbul Technical University,  Istanbul, Turkey.                                                                   e-mail:cagdas@itu.edu.tr

BArch. Gaye GÖZÜBÜYÜK                                                                                         Institute of Science and Technology, Istanbul Technical University,                                                          Architectural Design Master Program, Istanbul, Turkey                                                       e-mail:gayegozubuyuk@yahoo.com

Dr. Özgür EDİZ, Instructor                                                                                                                     Department of Architecture, Uludag University, Bursa, Turkey.

 

 

 

Abstract

In this paper, a computational design model based on the fractal dimension will be presented. Fractal dimension is used as a means of capturing the pattern appropriate at the compositional configuration of a historical architectural language and generating new forms, which will ensure the continuity of this language. In the first stage, architectural characteristics of a district with special architecture will be defined by calculating fractal dimensions in different levels. In the second stage of the model, this fractal values are used as input in computer program for producing form alternatives for the new buildings that will be designed in such places. This two-staged model, which is generated for the purpose of providing harmony between new and old, is applied to Chora, which is an important historical settlement of Istanbul. The generation process describes how to derive a compositional configuration from other forms with different dimensions, which can be generated by changing fractal dimensions.

1. Introduction

 

Computer supported design systems can generate different images during the early design process and provide useful inputs when searching for alternative forms of architectural design products. It is aimed that the generative approach which is used in this study will be used for supporting the creativity to produce architectural forms based on an existing architectural pattern.  Providing harmony in architectural design between old and new is a great problem for cities like Istanbul, which are growing around historical core. New buildings must be both unique and conformed to the proportional feature of the old buildings. In this way the proportional characteristic of original pattern of a historical environment or of a special environment is protected. In the development of this approach, the following stages have been carried out:

 

 

 

2. Fractal Geometry and Architecture

 

Geometry is the fundamental of the architectural discipline. It is a tool for describing thoughts of a designer for creating architectural product itself and its two and tree dimensional representations; drawings and models. For the purpose of creating architectural objects Euclid geometry has been used for ages. According to Bovill the reason of the influences of Euclid geometry being so strong in architecture is that architectural forms are man-made [2]. The researchers describe the relationship between Euclid geometry and architecture with the effects of mass-production in architectural design because the forms of building elements, which are produced with mass- production depends on Euclid geometry [3].

 

On the other hand the architectural design approaches based on nature revealed the effects of fractal geometry in architecture. Fractals - which were introduced by Benoit Mandelbrot in 1980s for describing the forms of natural objects, like coasts, mountains – have appeared in architecture with the details from a larger scale to the smaller one [4].

 

Although there are many examples, which based on fractal concept in the history of European, African, Asian and American architecture fractal geometry is begun to be used consciously in architecture with the new design approach in computational architectural design. Fractals could be represented by generative algorithms in computer with their major characteristics; developing through iterations, depending on starting conditions. In this way they could be used for designing forms, structures and surfaces alternatives [2]. 

 

In this study, fractal dimension is used as a means of capturing the pattern appropriate at the compositional configuration of a historical language and generating new forms, which will ensure the continuity of this language:

 

The aims of this study are:

 

 

 

3. Case study

 

In the case study, fractal dimension is used in two ways. Firstly it is used for determining fractal characteristic of a historical district in Istanbul and secondly it is used within a computer model for creating new buildings forms, which have the same fractal characteristic with this place for providing the harmony between old and new. For the case study, Chora (Kariye) district has been chosen.

 

Chora

 

The Kariye neighbourhood is located in the district Edirnekapi in Istanbul. The word Kariye (Chora) meaning "outside of the city", or "rural" is derived from old Greek [5]. In Kariye there are many monuments of the Byzantine and Ottoman periods. Kariye Church (Figure 1), Tekfur Palace (Figure 2), and Kastoria synagogue are some of these monuments.

 

      

 

Figure 1.Chora church   [6]                                                                            Figure 2. Tekfur Palace [7]

 

Chora Church, the symbol of the district is built on the site of a chapel, which is located outside of the city walls, by Justinianus. Several additions and repairs, which were made between the years 1315 – 1320, formed the current shape of the building. The mosaics and frescoes examples in Kariye Church are regarded as the most beautiful of the last period of Byzantine art. In the surroundings of the church, traditional Ottoman houses and streets are located. (Figure 3)

 

  

The buildings of which fractal dimension is calculated

The building in the place of which alternatives are generated

The buildings in the neighbourhood of the field study

Historical  buildings in the neighbourhood of the field study

 

Figure 3.  Site plan of the Kariye Bostani Street                                                                          

 

 

3.1. Kariye Bostani Street

 

The reason why this place is chosen for field study is the traditional architectural pattern of the street. There are both the examples of multi-storey buildings, which were built after 1950’s and of low storey buildings of traditional Ottoman Architecture near the street. Although the pattern of the street is protected in a large scale, the effects of chaotic architecture of the environment can be seen on the street.

       

Figure 4. The Protected side’s of the street           

Figure 5. The Protected side’s Silhouette of the street   

On the both side of the Kariye Bostani Street traditional Ottoman houses are located. (Figure 4, 5, 6) All the houses on the one side of the street are two or three storied wooden row houses and have a bow - window (cumba) on each façade.  (Figure 4, 5) On the other hand there are five or more storied concrete buildings, which are not in a harmony with these buildings, on the other side of the street. (Figure 7, 8)

                               

Figure 6. The other side of the street                        

Figure 7. The other side’s Silhouette of the street

In this study, a design model is suggested for providing proportional harmony between the forms of traditional buildings and new buildings and for protecting the street pattern.

Figure 8. 3D model of the current situation of the Kariye Bostani Street

4. Generating new form alternatives in Kariye Bostani Street

In the generation process of new form alternatives a computer model has been used [8, 9]. The model starts with the analyses about the Kariye Bostani Street. Fractal dimension takes the most important role in the analyzing level. For defining characteristic features of the architectural language of the Kariye Bostani Street, fractal dimensions in plan, silhouette and building scale have been calculated [10]. The fractal values obtained by using Bovill’s Box-counting method have been used as inputs in the computer program for composing alternative forms on the selected place in the street. (Figure 9)

With the aim of creating new forms according to the fractal values of the existing pattern, the place of the corner building which does not suit with the architectural characteristic of the Kariye Bostani Street is chosen for the project area.  (Figure 7, 8 building with colour blue) The new form alternatives are generated in the 18mx18m square shaped project area by defining the number and dimensions of initial shapes on x-y and z axis.  Therefore a grid system of boxes was superimposed over the project area on x-y axis [11]. In this way, dimensions of the initial shape have been defined.

                               

Figure 9. Form alternatives                        

In the next stage of the generation process two different initial shapes, a 3mx3mx3m cube and a as 3.60mx3.60mx3m square prism have been used for obtaining various design alternatives. In the last stage, fractal dimensions - which are calculated as 1.7 in the settlement scale and 1.2 both in the silhouette scale and building scale - have been applied to the initial shape for generating new forms. Finally, these generated form alternatives were tested on the 3D models of the Kariye Bostani Street and its surroundings, which were created in virtual environment. (In the first three alternatives, a 3mx3mx3m cube and in the fourth and fifth alternatives a 3.60mx3.60mx3m square prism has been used as initial shape.)

 

 

4.1 Form Alternatives

 

 

Figure 10.  Alternative 1

 

 

 

 

Table 1. Fractal values and the number of cubical units on x, y, z-axis, which have been used in

Alternative 1

 

Fractal dimension

Cubical units on the x- axis

Cubical units on the y- axis

Cubical units on the z- axis

1.7

6

6

4

     

 

Figure 11.  Alternative 2

Table 2. Fractal values and the number of cubical units on x, y, z-axis which have been used in Alternative 2

 

Fractal dimension

Cubical units on the x- axis

Cubical units on the x- axis

Cubical units on the x- axis

1.7

6

6

5

 

  

 

Figure 12.  Alternative 3

Table 3. Fractal values and the number of cubical units on x, y, z-axis which have been used in Alternative 3

Fractal dimension

Cubical units on the x- axis

Cubical units on the x- axis

Cubical units on the x- axis

1.2

6

6

5

 

 

 

 

 

Figure 13.  Alternative 4

Table 4. Fractal values and the number of box units on x, y, z axis which have been used in Alternative 4

Fractal dimension

Box units on the x- axis

Box units on the y- axis

Box units on the z- axis

1.7

5

5

5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 14. Alternative 5

Table 5. Fractal values and the number of box units on x, y, z-axis which have been used in Alternative 5

 

Fractal dimension

Box units on the x- axis

Box units on the y axis

Box units on the z- axis

1.7

5

5

5

 

 

5. Conclusion

 

One of the significant problems in architectural design is providing harmony between old and new. Fractal concepts have been come to use in many ways, both consciously and unconsciously, in the field of architecture.   

 

In this study, by relying on the fractal dimensions of an existing architectural pattern a generative design approach has been suggested which can be used in the process of supporting creativity in the creation of new forms and for testing harmony between old and new .By using the fractal dimensions of elements found in a shape library belonging to the relevant architectural language, this approach may show the way to the creation of architectural forms which will ensure the continuity of the pattern.

 

Using digital technologies while searching for alternative forms in the conceptual design phase is a new approach based on the development of new technologies. Using digital media as design media gives the designer the opportunity to expand his/her imagination and innovations.

 

By placing the three dimensional form alternatives in the settlement model, harmony has been tested with the existing architectural language.

 

 

 

References

1.      Ediz, Ö. (2003) A Generative Approach in Architectural Design Based on Fractals, PhD Thesis, Institute of Science and Technology, Architectural Design Graduate Program, I.T.U (Advisor: G. Çağdaş)

2.      Bovill, C. (1996). Fractal Geometry in Architecture and Design, Birkhauser, Boston

3.      http://classes.yale.edu/Fractals/  (October 2004)

4.      Mandelbrot. B. (1983) The fractal geometry of Nature, W. H. Freeman And Company,  New York

5.      http://www.kulturturizm.gov.tr/portal/arkeoloji_en.asp?belgeno=2994 (October 2004)

6.      http://tr.wikipedia.org/wiki/Kariye_Camii ( November 2005)

7.      http://www.kulturturizm.gov.tr/portal/muzeler_tr.asp?belgeno=2505 ( November 2005)

8.      Ediz, Ö., Çağdaş, G. (2004) A computational architectural design approach based on fractals at early design phases, ECPPM: eWork and eBusiness in Architecture, Engineering and Construction, Taylor & Francis Group, London

9.      Ediz, Ö., Çağdaş, G. (2005) A generative approach based on fractals in architectural design, ITU Journal / a, Vol: 4, no: 1, pp: 71-83

10.  Gözübüyük, G. (2005) Fractals and architecture, Project I Report Institute of Science and Technology, Architectural Design Graduate Program, I.T.U

11.  Gözübüyük, G. (2005) Generation models of fractals and cities, Project II Report Institute of Science and Technology, Architectural Design Graduate Program, I.T.U