Today, almost every town in Europe has a district of mass housing estates. Especially European countries, which were in the former Soviet Union, are facing ample issues on dealing with mass housing districts, which cover a great part of cities. Most of them are in a critical condition and in necessary need of renovation. Nevertheless, they are strongly criticized by researchers, as uncomfortable places to live, which do not fit the human scale. These post – Soviet mass housing estates, which are called ‘microrayons’, is an immense headache to all post - Soviet countries. Riga, which is the capital of Latvia and the biggest city in the Baltic States, can be considered as a special case because of its historical and political situation. While in the past, serving as a western hub for the former USSR, today it is an independent city which is located in a democratic country. Despite the fact that Riga’s historical center is included in UNESCO world heritage list because of its unique Art Nouveaux/Jugendstil architecture, almost one third of the city is covered with post – Soviet mass housing estates. Mežciems is one of them. Once been a soviet ‘microrayon’, today Mežciems is a challenging place for sustainable urban reconstruction. Sustainable transformation of ‘microrayons’ sounds like a promising future. Sustainable development is based on creating comfortable zones for humans, practicing the use of renewable resources and developing a nature friendly environment. While sustainability itself is focused on the future, not only the present. In this project the case of Mežciems is investigated. Mežciems was chosen because of its unique location and surroundings. Crucial was it to find appropriate approaches of sustainability which could be implemented in Mežciems ‘microrayon’. The ones which extend the life of Mežciems, preserve the history and improve urban structure of the whole city, were used. In order to understand the scale and the real situation of Mežciems, on - site investigation, literature studies and analysis were done. From these it was observed that Mežciems as well as other microrayons possessed many problems. Thus some strategies are used in this project to show that these problems can be solved in the most economic and efficient way. This ends by proposing a new design which if implemented, would transform Riga into an attractive and sustainable city. These strategies also have the potentials to transform other areas plagued by the problems associated with mass housing estates.