This thesis examines the evolution of the urban typologies implemented in the urbanism of Stockholm suburbs departing from the case study of Hammarby Sjöstad, a prominent example of sustainable urban development from the 1990s. It critiques the traditional approach to sustainability, often confined to technical solutions and based in models or best practices to be replicated. Instead, it explores sustainability as a process; an approach that incorporates principles of aggregation, participation, and contextual responsiveness. By tracing the historical development of urban and suburban structures, from the 17th century absolutist state to the welfare state, the thesis highlights how urbanism has evolved through four key phases: internal aggregation, external intervention, core regularisation, and territorial expansion.

The study argues that the block typologies and grid scheme applied in the sustainable urban design are not a departure from functionalist urbanism but a continuation of it, shaped by larger political and economic forces. It follows its evolution from examples of late functionalism, through two precedents of Hammarby Sjöstad, the housing areas of Kv. Dalen and Skarpnäck, that situate already in the late 70s, the perimeter block in the suburb, and which put it in relation to slab typologies of late functionalism, but also with the garden city. What opens the door to propose a nuanced account of 50 years of functionalism.

The aim of the thesis is not to produce a descriptive analysis, but to develop ways to confront the practice of urban design, and an approach to the historical evolution of urbanism that can help to inform future intervention in the city. Drawing on disciplines related to history, the cases are studied in relation to the dominant trends and to the political, economic context of their time, to understand better the mechanisms behind the materialisation of the space. Through the research are discussed driving forces that influence urbanism (aggregation, the bureaucratic and centralised state, capitalism, individualism, and sustainability) and different paths for urban design (romantic-expressionism, rationalism, a middle ground between them, utilitarianism, and dialogue) that have continuity in different periods. The thesis thus proposes to read each urban area not as a generic model, but as the convergence of driving forces that influence form, the dominant style of the period, and the path chosen to confront urban design. Under this perspective Hammarby Sjöstad falls in a moment of change of paradigm in the way urbanism is approached, what situates it at the end of two processes. The construction of the suburb between 1905 and 1995, and the construction of the city by the bureaucratic and centralised state between 1600s and 1995. The suburban block, discussed as an evolution from the linear slab buildings that are regrouped to embrace the park and recover the street in the perimeter, has been named `park in the block. A notion that connects with the well known `house in the park characteristic of the garden city of the beginning of the century. Between both, evolves gradually the `slab-house in the park, the lineal buildings of functionalism. The thesis further proposes suburban regularisation as a crucial next step in urban sustainability, advocating for a more integrated approach to urban growth that fosters active citizenship.

By reinterpreting the urban development of Hammarby Sjöstad and its predecessors, this work offers a framework for understanding contemporary urban transformations and the ongoing tension between design, policy, and societal change. The research suggests that sustainability cannot be seen as a singular unitary model but as a set of guiding principles and practices such as dialogue, aggregation, and adaptabilitythat contribute to a more sustainable urban future.