Pre-print: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=6308998
This paper examines material use, material intensity, and embodied greenhouse gas (GHG) emissions across five real refurbishment, renovation, and adaptive reuse projects in Canada and the U.S. The study quantifies materials removed, retained, and added. We find that 60 to 98% of original structural mass was preserved, reinforcing the role of existing buildings as material reservoirs. New additions often used lighter assemblies, reducing whole building material intensity by up to 42% in some cases. Despite strong material retention and efficient use of lighter systems, all final buildings exhibited higher embodied GHG emissions than their originals, with increases from 1% to 60%. This rise reflects the carbon intensity of new materials, particularly insulation, windows, and concrete, regardless of mass. The study provides one of the first detailed datasets on material flows in existing buildings interventions and highlights the need for broader, regionally diverse research.
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