**2. Importance of urban housing patterns for sustainable urban development**

As Burton, et.al. (2000) cite, the last decade has witnessed a burgeoning interest in the concept of sustainable development. In particular, the need to develop sustainable cities, in other words to achieve sustainable urban development, has become a global political aim. In fact, sustainable development summarizes the challenges that the world is facing; to manage a global social and economic development, which neither deteriorates the ecological systems, nor exhausts the natural resources. Cities have been given a central place in

another official report, the Strategy for the UK, "A Better Quality of Life" published by the UK Government in 1999, sustainability was defined as the simple idea of ensuring "a better quality of life for everyone, now and for generations to come". The quality of both the natural and the built environment, the perceptions of one's neighbourhood, the opportunities provided by the environment for self-betterment and community building, and the extent of real and perceived ownership, all influence quality of life. However, cities are no more sufficient to meet the psychological, social and cultural needs of their residents. In view of these circumstances; reasons of this insufficiency and alternative ways of

In the light of these, the scope of this chapter is determined as examination of different housing patterns of Bursa in the context of sustainable urban development. Bursa is one of the most important Anatolian cities which comprises the oldest and most authentic examples of monumental and civil architecture and which combines rich tradition, culture, history and nature at the same time. It is a valuable city shaped by a rich cultural heritage and succeeds to reach our times without losing its importance. In the south of the Eastern Marmara, Bursa has been one of the oldest settlements in Anatolia and the first capital of the Ottoman Empire, due to its geographical location, agricultural convenience of its natural structure and its importance from military point of view. Today, being the fourth biggest city of Turkey, Bursa is economically very dynamic and has been undergoing a rapid industrialization and urbanization process. It has one of Turkey's highest population increase rate as a result of its being a focus of large inner and outer immigration. There has been a huge migration from other regions as well as from Balkanic countries since 1950s. For these reasons, unfortunately, the unique historic identity of Bursa has suffered a lot, however the city is still withstanding the onset of rapid urbanization. The author puts stress on the changes in urban housing patterns of Bursa caused by the immigrants and their

impact on the form of the city, in the context of sustainable urban development.

development of the city, offering some strategies and implementation policies.

This chapter consists of six sections which includes an introduction on urban development process in Turkey. The second section highlights the importance of urban housing patterns to achieve sustainable development dealing with the theoretical literature on the related concepts and indicates the relationship of sustainable urban development and urban housing patterns. The effects of migration on the development trends of housing environments in Turkey and urban development and housing processes in Bursa are explained in the following sections. The fifth section covers an analysis of the immigrant housing patterns both around the historic city center and in periphery of the city. The paper concludes with a discussion on the effects of immigrant housing districts on the sustainable

**2. Importance of urban housing patterns for sustainable urban development**  As Burton, et.al. (2000) cite, the last decade has witnessed a burgeoning interest in the concept of sustainable development. In particular, the need to develop sustainable cities, in other words to achieve sustainable urban development, has become a global political aim. In fact, sustainable development summarizes the challenges that the world is facing; to manage a global social and economic development, which neither deteriorates the ecological systems, nor exhausts the natural resources. Cities have been given a central place in

solutions should be investigated.

discussions about sustainability problems, because in cities many people live closely together and are engaged in a large number of activities. As a socio-cultural entity the city fulfils a number of functions for specialised types of people, whose occupations and social roles differ from those of rural dwellers (Hatfield Dodds, 2000, Gullberg, et.al., 2000). Where and how people live play an important role in achieving sustainable development both in physical and socio-cultural contexts.

To understand how certain groups are allocated to certain parts of the city it is important to understand the urban housing market. The housing stock of a city constitutes more than just accommodation; it is a link with the past, a record of history, a silent witness to the periods of city growth and decline, especially in historic cities. In historic cities, changes concerning home environments show a dramatic transition procedure from past to future; from tradition to modernity. On the other hand, the specificity of a historic cityits identity, history, culture and distinctiveness- has very close relationships with diversity and complexity of urban housing patterns, which are directly related with socio-cultural, socio-economic and political structure of the city. These arguments show that the immense diversity and complexity of housing within different neighborhoods, cities, and countries, and their effects on sustainable urban development are worth emphasizing.

Housing constitutes the largest space user in the city and has always played an important role firstly in shaping urban regions and then achieving their sustainable development. The operation of the supply and demand for housing divides different groups of people to different types of housing in different parts of the city. The result is a rich residential mosaic which can be named as urban housing pattern. It is not a static but dynamic phenomenon due to fluctuations in additions to the stock, demolitions, and conversions. (Short, 1996), (Knox, 1994), (Hartshorn, 1992).

The decentralization of employment and commercial functions, and out-migration of higher income groups to newer peripheral housing change urban housing environment and weaken neighborhood viability. By this way the process of residential decline begins with the transformation of rural land to residential use, and then higher-density apartment construction in inner rings together with population and density increase. The last stage is the renewal of obsolete areas, with the construction of moderate -or low income multiplefamily housing or luxury apartments (Hartshorn, 1992). All of these stages bring about unsuitable conditions to achieve sustainability in cities.

There is much more diversity in housing conditions among Third World countries than there is in the developed world. Housing conditions and housing problems of the two worlds are quantitatively and qualitatively very different. Third World countries vary from each other in all fields including housing systems, policies and stocks. The only common denominators are low levels of income, a limited inheritance of quality housing, inadequate investment in residential infrastructure, and high levels of urbanization (Bourne, 1981). The urban housing market of the third world can be identified in two distinctive social and spatial patterns. While the upper and middle classes are living in well-constructed, even luxuriously designed and landscaped houses, the poor are in the high density slums typically on the periphery, called squatter settlements and typify many cities of the Third World. Some of them are temporary, others are more permanent and better organized; but

The Impact of Different Urban Housing Patterns on the

"deterioration" became predominant (Şenyapl, 1998).

procedure (Tapan,1996).

Sustainable Urban Development of a Historic City, Bursa/Turkey 185

squatter (Erkut, 2000). As Şenyapl (1996) indicates, the gecekondu phenomenon has a past of half a century in Turkish cities, similar to what happened in many large cities of Third World countries. They are self – help built housing units on public land and there is no differentiation between the owner, the user and the builder of these houses. Starting with 1970s, builder and owner of gecekondu differed from each other, which led to the commercialization and decrease in environmental quality. After 1980s, market value dominated in Turkey and an informal market started with its own rules and operating system, which does not allow the ordinary migrant to build a gecekondu anymore. Erkut (2000) summarizes this process as follows; the "use value" of houses was the dominant characteristic of the first generation gecekondu. Throughout time, the commercialization of the gecekondu process resulted in the construction of informal settlements that created illegally subdivided lands which are either rented or sold. The "market value" is the dominant characteristics of second generation of gecekondu. The development process of gecekondu areas after 1980s is explained by Şenyapl (1999) in a very clear way. He points out that the peripheral areas of cities in which formerly only the gecekondu population was interested started to become popular with higher income groups who tried to get away from the disturbing conditions of cities and they began to be used for building collective housing units, mid-income group cooperative houses and private houses. The gecekondu areas close to city centers and transportation networks gained more value and were taken over by large companies to build multi-storey apartment blocks. On the other hand the agricultural lands were sub-divided into plots to be sold and small illegal apartment blocks were built over these plots. In the existing gecekondu areas for which reconstruction plans could be obtained, the owners whose lands were large enough and close to the main roads and centers were having small apartments built by contractors, while others were setting up similar two- or three-storey apartments themselves by using their own family resources, with no regard to environmental standards and reconstruction rules, just as they had done when building gecekondus. The remaining lands awaited the opportunity of being converted into apartments, and the owners of gecekondus who could manage to move into small flats, started to rent them out. Thus, this new development model did, for the first time, lead to the replacement of the organized and neat gecekondu districts by areas where widespread "moving" and

In developing countries, social housing (mass housing) areas are alternatives to squatter settlements. The social (mass) housing concept defines the housing production which has arisen as a result of projects aiming at producing a large number of dwellings by public or private associations for the low- and middle-income groups, in other words, for those who cannot acquire a dwelling through their own savings. They can be grouped into two; as the first group, providing multi-storey apartment blocks for rent or ownership produced by public associations, and as the second group, providing land with infrastructure or land together with a partially built dwelling supplied by the state or local governments for low income groups, with the aim of turning a self-help housing production into a planned

Tapan (1996) claims that the mass housing applications in Turkey have brought along a new urbanization model with a planned physical development. The mass housing projects usually produced outside the existing urban area are not affected by the urban fabric. They

most are unplanned, with low quality housing, high unemployment, and insufficient social services. In some areas, these spontaneous residential settlements represent from one-third to one-half of the total population of the metropolitan area (Bourne, 1981), (Hartshorn, 1992).Today, all of these characteristics are assumed as indicators of unsustainability. Jenks (2000) discusses the suggestions which are made to overcome the unsustainability of peripheral development through the tax system in the formal sector, and inclusive processes in the informal sectors. However, it is an approved fact that these kinds of precautions in terms of material arrangements are not enough to achieve sustainable development of any urban area.

The main idea to emphasize is that the urban housing pattern is fracturing the city into distinct areas which are the basis for identifiable communities of shared attitudes, adopted as the basic actors of sustainable urban development. As Short (1996) points out, the identification of these communities and their creation and restructuring is a very important topic for housing all over the world. This shows that, it is an important necessity to examine urban housing process both in spatial and socio-cultural dimensions. In the last decades, researchers studying on the concepts of sustainability and sustainable development agree on emphasizing this necessity and have consensus on two distinct requirements of sustainable development; physical and socio-cultural. Physical requirements of sustainable development can be classified under the headings of "high quality of life", "optimum density", "minimum energy and resource use". On the other hand, socio-cultural requirements can be classified under "changes in world views", "development ethics", "awareness and responsibility of environment and sustainability" and "participation in the sustainability studies" as the leading keywords (Çahantimur,2007). In this study different patterns of immigrant housing in Bursa are analysed in terms of physical requirements of sustainable urban development. The subcomponents of these requiements were identified by the author as follows: physical environment conditions, vitality/diversity, accessibility, flexibility, safety and efficiency of the environment as the subcomponents of "high quality of life", density of people, density of buildings and density of functions as the subcomponents of "optimum density", use of recycled materials and systems, minimum use of motor vehicle as the subcomponents of "minimum energy and resource use" (Çahantimur, 2007). First of all, urban development process in Turkey, explaining the effects of internal and external migrations will be summarized in the following section.
