The built environment is a major consumer of energy in which many improvement steps have to be made. This project investigates how energy can be more efficient by reducing, reusing and producing energy on an urban and building scale. The research showed that the implementation of a sustainable collective heating system around the Palace of Justice can significantly reduce the energy consumption for heating. Comprehensive renovations improving the building energy performance reduce the energy consumption to a minimum. The proposed sustainable integrated renovation of the Palace of Justice shows what such renovation can look like. The combination of modern sustainable techniques and more common interventions opens up the traditional approach to energetic sustainability resulting in a monumental nearly zero energy building. With its role as an energetic catalyst, the addition of public functions and the increase of accessibility, the Palace of Justice is firmly embedded in the city and society and can therefore last for many years to come.