A large part of the waste volume in Switzerland, and in the canton of Bern, is mineral waste in the form of excavated and demolition materials, as well as residues from municipal/industrial waste- and wood incineration. These materials are nowadays deposited in landfills in large quantities, as they often don't meet the quality criteria for recycling. This places a heavy burden on the country's limited landfill volume. At the same time, valuable raw materials are also lost to the mineral resource cycle. The procurement of new building materials, or primary raw materials, is very energy- and CO2-intensive, thus the recycling process reduces the amount of waste and its environmental impact. The output, resulting from secondary raw materials, can be used in the domestic construction industry. In order to conserve primary raw material reserves and close material cycles in a sustainable way, the end-of-pipe mentality must change. The project ""Substitute Raw Materials in the Circular Economy"" makes a valuable contribution to addressing these issues by creating the necessary basis for recycling secondary raw materials. The project aims to investigate the material currently deposited in landfills as well as their potential for recovery, recycling and up-cycling. This includes: concrete demolition waste; excavated and quarried material; fractions from processing plants; bottom ash from municipal solid waste incineration (MSWI); and wood ash. In a second phase of the project, implementation experiments will be performed (e.g. on a laboratory and pilot scale) with promising material streams. The project is intended to build the knowledge basis for establishing the maximum use of secondary raw materials in the long term. The gained knowledge may later be applicable nationally as well as internationally.