Working on the basis of our views on the material, we formulated nine sustainability aspects, from which the Zuidkas concept emerged almost as a natural conclusion. Taking issues like CO2 reduction, energy savings and public health into account, we arrived at a functional mix in the building that is far from ordinary: homes, offices, a school, parking facilities, retail, restaurants, a park and a biogas electrical plant. All of these functions can be connected by a glass envelope that accommodates a variety of ‘greenhouses’: CO2 greenhouses, hybrid greenhouses, a buffer zone and various atria. The objective was to make an intelligent autarchic building that allows for the exchange of energy and CO2 streams and the conversion of waste streams into heat and energy. As well as minimising the building’s total emission levels, bringing back the building’s energy requirement to minimum levels, and above all creating an attractive, comfortable and healthy environment for people to live and work in. To develop the building as a miniature city, embedded in the proposed urban structure of the Zuidas. A sustainable Unité d’Habitation.