Kristina Bringedal Gedde
PhD Candidate
Authors
Kristina Bringedal Gedde Georgios Triantafyllidis Alessio Miatto Lone Ross Lizhen Huang Daniel Beat MuellerAbstract
Abstract The building sector accounts for a significant share of global material stocks and embodied greenhouse gas emissions. Material intensity (MI), defined as construction materials per unit floor area, is a key metric for understanding resource use and environmental performance. Existing approaches estimate MI for specific building types and cohorts but rarely explore additional factors that influence the structural element requirements. This study refines traditional methods by incorporating building geometry, number of floors, geographical context, construction methods, and regulatory changes, using Norwegian residential buildings as a case study. We focus on stud use in exterior walls to understand how their MI (kg/m 2 ) varies across buildings. Our correlation analysis reveals that construction year (ρ = 0.69) and energy efficiency standards (ρ = 0.51) are associated with higher MI of studs while building length shows a notable negative correlation (ρ = –0.38). Timber stud MI increases with footprint complexity and number of floors but decreases as building length and floor area grow. Snow load further contributes to increased stud MI. Studs' MI also varies across periods, reflecting changes in regulations and construction practices. These findings enhance our understanding of material use drivers in timber structures and provide a foundation for developing more nuanced building stock models to improve resource efficiency assessments and support targeted climate mitigation strategies.
Abstract
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Abstract
Post-Consumer Wood (PCW) is a valuable resource that could substitute virgin wood in many applications. However, its integration into the wood processing chain requires detailed information on composition, content of contaminants, size, and shape. Here, PCW collected over eight months from three sorting facilities in southeastern Norway was analyzed for suitability in recycling. Shredded PCW from 24 samples was manually sorted based on material origin, analyzed for heavy metal concentrations, and the particle geometry was measured with an automated laser scanner. Based on the results, 39–67 % of the mixed PCW was made up by clean wood particles suitable for recycling. Wood-based panels within the PCW were not only a source of contaminants (adhesives, coatings) but also decreased the length-to-width ratio of the resulting particles and chips. The median heavy metal concentrations did not exceed the limit values issued by the European Panel Federation. However, individual samples and the fine fraction (< 8 mm) exceeded these limit values. Manual pre-sorting before shredding into chips increased the share of clean wood particles, prevented elevated fiberboard contents and significantly reduced heavy metal concentrations.
