**1. Introduction**

Throughout history, cities have been built to serve a variety of functions; as forts, market places, and as centres of administration or industry. All cities have experienced periods of growth and decline and all tend to raise contradictory views concerning the nature and purpose of the city as an urban system (Elliott, 1994). Over the last fifty years cities have been transformed from fairly concentrated and identifiable towns into amorphous urban areas, sprawling into their hinterlands without any visible borders between town and country. Transition from the industrial society to the information society as well as the globalization process led to changes in space and spatial organizations; thus, most of the cities around the different regions of the world have been subject to important social and cultural alterations. As a result of this urban transformation process around the world, different physical and social structures emerged in different regions.

The developments in political, economical and technological fields caused a very rapid urbanization in Turkey. However, providing sufficient number of residences that are available for people with average income as well as constructing the substructure necessary for these residences have not been succeeded; therefore, a lack of healthy accommodation problem, which is typical for underdeveloped or developing countries, has arisen. Besides the very high level of migration from rural to urban areas due to the rapid industrialization, Turkey has also been influenced by the migrations from abroad. Tekeli(1998), indicates that, squatters, build - and -sell apartment blocks and cooperative housing societies as well as housing financed by the state have emerged as solution to these problems in this country. He also points out the fact that none of these presentation forms has been a form to enrich the life quality nor to create good quality environments. Moreover, "Pull down-rebuild" processes in the city centers led to the demolishing of historical and cultural values, to the permanent density increase, to the loss of green areas as well as to the insufficiency of the social substructure. The urban development in the cities caused a permanent decrease in quality of life, which is determined as the main indicator of sustainable urban development by many researchers (e.g.Redclift, Woodgate,1997;Mitchell,2000). In the report of WCED (1987), the concept of sustainable development has come to be associated with efforts to increase the quality of life without endangering the natural resource base of the society. In

The Impact of Different Urban Housing Patterns on the

physical and socio-cultural contexts.

emphasizing.

(Knox, 1994), (Hartshorn, 1992).

unsuitable conditions to achieve sustainability in cities.

Sustainable Urban Development of a Historic City, Bursa/Turkey 183

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

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

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),

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

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

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 solutions should be investigated.

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.

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