In Scandinavia today many old harbour areas are developed into residential and commercial areas. For example are both Helsingborg city and Malmoe city in south Sweden planning to restructure some of their harbour areas to accommodate shops, schools, offices, residences et cetera. In Copenhagen in Denmark new plans for Nordhavn is also underway. In almost every plan proposal to redevelope an old harbour area the harbour activities are set a side to give room for new development. In Reykjavik, however, this has not been the case. In the international architect competition for the old harbour of Reykjavik in 2009 the main goal was to receive proposals on how to combine residences, shops and offices with ongoing harbour activities. That required a new form of planning and especially a deepened awareness and consideration in harbour redevelopment. This master thesis will focus on that kind of harbour redevelopment with the old harbour of Reykjavik as a specific subject of interest. The main question for the thesis is: How can ongoing harbour activities be combined with a diversified city environment, with room for residences, culture, leisure, tourism and commerce? As a result of lack of literature and information regarding harbour redevelopment with contained harbour activities a method to find important and relevant aspects in this field has been utilized. The method procedure has been to broadly look at three ongoing Scandinavian harbour redevelopments (H+ projektet in Helsingborg, Västra hamnen in Malmoe and Nordhavnen in Copenhagen) and compare them with planning aspects presented in the New urbanism and Compact city ideologies as a way to identify distinct similarities or differences. Through a discussion of the results of the analysis a conclusion of important aspects to consider in a harbour redevelopment has been identified. Based on the conclusion of the analysis the prerequisites of the harbour is later discussed in order to obtain a deeper understanding of the harbour conditions. Through this discussion and the conclusion of the analysis the main question of the thesis is answered and illustrated with a plan proposal.