Circular resource management in a land clearance scenario: Sollihøgda Plussby case

Abstract: The construction of cities involves the use of land for new spaces and infrastructure. Construction on undeveloped land poses a dilemma on how to deal with the natural resources found on the construction site. Circular economy could provide guidelines on how to harness these resources, so they become products that circulate through as many cycles as possible, therefore decreasing resource consumption and waste. This research aims to explore alternatives to harness the natural materials extracted during the land clearance process of a new urban district: Sollihøgda plussby. Additionally, a new method to examine the circularity of the suggested products will be tested: the longevity indicator. The method of this thesis consists of three parts: (1) an inventory to define which natural materials are found in the construction site and their main characteristics, (2) interviews with industry experts to gain a technical insight on the possible uses for the materials, and (3) a longevity indicator to measure the circularity of the proposed uses. This research found that the forest in Avtjerna consists of Norway spruce, Scots pine and birch. The sediments are mostly humus with a turf sheet cover, while most of Avtjerna’s bedrock is categorized as rhomb porphyry lava. Norway spruce and rhomb porphyry lava have the required quality to become high-quality products for the construction industry, and they could be used directly in the project. High-quality products have longer lifetimes and more possibilities of recycling and reuse, therefore they scored higher when calculating the longevity indicator, which means a higher material retention. The other materials (Scots pine, birch, other sediments and rocks) have also possibilities of becoming products that could be used in Sollihøgda Plussby, but the longevity indicator for these materials was lower than those of Norway spruce and rhomb porphyry. Despite the usefulness of the longevity indicator to provide a preliminary assessment, this method needs to be upgraded so it incorporates other CE parameters. There should be a distinction on how many times the material is recycled, the lifetime of the recycled products, and the quality of the products obtained from the recycling process. Inventorying the natural resources on a construction site is a practice that should become common, since it allows to determine how materials can be harnessed, but also which areas should be preserved due to their ecological value. Additionally, the longevity indicator should not be used in isolation, but the environmental impacts of each suggested product should be assessed too.