The work behind the Takryttaren residential project in Uppsala, Sweden, shows how major climate gains can be achieved when contractors and material suppliers collaborate at an early stage. In this project, the climate impact from concrete has been reduced by up to 60 percent. The result is not based on a single product or a new mix-design. It is based on a theoretical study and a structured way of working where theory and practice are combined into a model that is already helping shape the future of construction.