CARBON MITIGATION STRATEGY WITH ENGINEERED TIMBER: THE CASE OF MJØSTÅRNET

Abstract

Mjøstårnet is a building that applies sustainable construction principles throughout its lifecycle, with timber as the primary building material. The use of timber, particularly locally-sourced and prefabricated timber, contributes to improved environmental performance by reducing transportation-related emissions, minimizing construction waste, and offering carbon storage potential during its service life. This research aims to explore opportunities to further reduce embodied carbon in the building by proposing alternative material scenarios. The study employs an embodied carbon assessment focusing on slab construction, which represents one of the largest contributors to upfront embodied carbon in the building. Alternative scenarios include replacing slab materials with cross-laminated timber (CLT) and fly ash concrete with varying substitution levels. The results indicate that replacing conventional slab materials with CLT can reduce embodied carbon by 25.59%, while the use of fly ash concrete with a 40% replacement level achieves a reduction of 14.07%. The combined application of these strategies demonstrates a potential embodied carbon reduction ranging from 29.47% to 39.81%. These findings confirm that material substitution, particularly in slab construction, is an effective strategy for mitigating embodied carbon in sustainable building design.