Today, urban transformation projects, which are performed to combat physical and social deterioration in cities, are frequently discussed in terms of structural and administrative aspects, we also need to bring a new perspective for awareness and redefinitions on current practices. We know that while the regeneration projects stimulate local economic growth in the short to medium term, there are lots of physical, social and environmental problems. This study estimates the local effects of urban transformation policies of applications by using evidence from interventions that took place in medium-sized cities in Turkey. Urban transformation is a set action which consist of laws, policies, economic decisions, and spatial improvement preferences. Urban transformation has a process in which the diversity of impact factors is high, so it includes some forms of partnership that operate between different stakeholders. The paper is aimed to establish a series of relations with the focus of "the mechanism of urban transformation influence on physics-space and process" by examining the positive and negative aspects from the decision and design process to the reconciliation and construction. The chosen case is Kayseri Sahabiye Neighborhood Urban Transformation Project, which is still under construction. The transformation land is located in central business area of the city and it is easy to access from many points of the city. It is also an area where buildings belonging to the Seljuk period and modern civil architecture examples of the Republican period are intertwined. Therefore, every urban intervention planned in this area requires differing approaches rather than one set discipline. The reason for choosing this area is that the transformation project was obtained through an architectural competition. The other reason is that there is so much complex challenges in order to design the habitable new urban area. New project area, which includes mixed functions such as trade, office, and residence, is 51 hectares. The area is divided into 8 stages at the construction phase and first stage was finished in October 2020. There are 622 residences and 55 shops. The research has 2 effect levels. The first of these is the effects of urban transformation about physical, social, environmental and economic changes that are experienced in the present and will be experienced in the future. The other effect level is the determination of the defects or problems encountered in the functioning of the process and their effect mechanisms on each stage of the process. The research was conducted with method of questionnaire. For the reliability of the research, the survey was completed by considering the number of 60 households, which corresponds to approximately 10% of the number of houses. According to the first level results of the survey (physical changes effects); while the organization of space in residences is adequately designed, it has been emphasized that the new residences will not fit the living cultures of the users in spatial terms. It has been emphasized that the concerns that the excess number of residences and different living conditions in the new project will break the neighborhood relations and that social integration will not occur. In addition, the transition from a low-density residential fabric to a high-density life has caused serious security concerns in users.