The 13th International Symposium on District Heating and Cooling will take place in Copenhagen, Denmark, from 3-4. September 2012. The general idea of the symposium is to bring together academic and industrial researchers from different countries to keep in touch with the latest research and development trends in the field of district heating and cooling. The International Symposium was founded by the five Nordic Countries and has a more than twenty year long tradition. It is the most significant international conference within this area of research.