In order to significantly lower the environmental impact from human activities, numerous efforts and approaches related to the transformation of human activities have developed during the last decades. Examples of such efforts are policies and strategies at different levels, some with a top-down approach focusing on extensive institutional changes, and some with a bottom-up approach focusing on industrial actors and industry-led activities. One essential aspect of these efforts concerns the energy used producing the products and services provided within our society. This includes, for example, improved efficiency of processes in order to minimise the amount of energy used, or optimisation of efficiency by using energy with the lowest possible exergy value. It can also be about re-use of energy, which is the focus of this thesis. Heat, which is the main by-product of all energy systems, can be utilised for heating purposes to lower the primary energy demand for heating. Increased utilisation of excess heat, however, requires collaboration between normally unrelated actors, those with a supply of and those demanding excess heat. In Sweden, which is a Northern European country with high demand for heat, the tradition of large energy-intensive manufacturing industries generating large amounts of excess heat, in combination with well-established district heating distribution systems, constitute good conditions for excess heat utilisation. Despite the fact that Sweden is among the world leaders in utilising excess heat, there is however, still a large unutilised potential. From this background, the objective of this thesis is to identify challenges behind excess heat utilisation for heating purposes, and to propose practical suggestions to facilitate expanded excess heat utilisation. The overall objective is analysed with a focus on drivers and barriers behind interorganisational collaborations on excess heat utilisation, important components of interorganisational business models and how the technical conditions regarding supply and demand could be facilitated by strategic municipal spatial planning processes. The research is largely based on interviews conducted with societal actors with different perspectives on excess heat utilisation; energy companies, industries generating high-grade excess heat, facilities generating low-grade excess heat, facilities demanding low-grade excess heat, experts of utilisation of low-grade excess heat, branch organisations, municipal spatial planners, energy- and climate advisors, and developers. Document studies have been conducted in order to collect case specific knowledge. The research questions are explored based on literature studies on the principles of industrial symbiosis, business model perspective and strategic planning. Further, they are examined in a Swedish context. It is concluded that the three perspectives complement each other by providing a system perspective on increased utilisation of excess heat as they seek to contribute both environmental and financial benefits at both a company and societal level. In order to facilitate further utilisation of excess heat it is important to focus on the organisational factors of humility, honesty, transparency, trust, fine-grained information transfer, joint problem solving, and shared visions of common goals, which are important conditions behind development of functional and long-term durable collaborations. Business models for collaboration could contribute to the creation of these organisationally important conditions. Such business models could also provide knowledge on how to create and capture joint values. For some collaborations involving actors lacking the technical knowledge related to the capturing and distribution of excess heat, a third-party providing services related to the technical knowledge required could be beneficial. Collaborations in which one of the actors consists of an energy company often entail the technical knowledge required. This implies that different collaborations involving different types of actors and under different prevailing financial, technical and organisational conditions require customised and flexible business solutions. Local authorities could, through their overall function, initiate interorganisational collaborations on excess heat within the framework of municipal spatial planning. The results do however show that the investigated planning processes could develop more extensive stakeholder participation to include further societal actors related to excess heat. More extensive stakeholder participation, have the potential to initiate new development of collaborations on excess heat between normally unrelated actors, both with and without involvements of third-party knowledge brokers. A broader participation is also expected to result in increased knowledge on how to plan to further facilitate the condition of excess heat utilisation.