"The master thesis deals with general conditions of the development of brownfield sites in Poland. Particular regard is made to the discussion of strategies for the activation of post-industrial fallow land under the ""MiÍdzytorze-Areaî in Gdynia. The topicality of this theme is evidenced by major projects such as the conversion of the port on the Vistula River in Warsaw (Port Praski) and the future use of the docklands area in GdaÒsk (M_ode Miasto). Large-scale conversion projects are characterized by their high degree of complexity, long realization horizon, and huge capital expenditure requirements. For this reason the type of cooperation focused on is the Public Private Partnership (PPP). By means of the MiÍdzytorze-Area reference example a PPP model has been developed and various instruments for its implementation have been discussed. The current general conditions for town and real-estate development in Poland have been highlighted and strategies for the successful and sustainable accomplishment of such challenges have been developed. The requirements of the work lie in the preparation of proposals for overcoming the still dominating sectoral approach to an interdisciplinary and integrated approach. The goal is a discussion of the controlling general conditions with regard to the 2005-adopted polish PPP Law and the resulting consequences for the real-estate industry. Reference to the current global discourse on the sustainability principle in real-estate and urban development is made with the thematic focus being on projects for the revitalization of inner-city areas, and the particular situation of Poland is placed in an international context."