Just one more storey? The embodied greenhouse gas impacts of adding height, slab thickness, building code and design tranches

Societies across the globe are simultaneously trying to build much more housing while drastically reducing greenhouse gas emissions. This is precipitating debates about the nature of sustainable housing. ‘Conventional wisdom’ holds that taller buildings are worse for the environment coinciding with longstanding skepticism of height, yet the research and data is often anecdotal or incomplete and contradictory. This paper contributes to the discussion by examining how building height affects embodied emissions for new 5-to-20 storey reinforced concrete residential buildings. We find that while height contributes to embodied emissions, its impact is smaller than slab thickness and design tranches within the studied storey range, which offer more effective opportunities to improve resource productivity, reduce material intensity and associated embodied emissions, without reducing building function. Our findings encourage a shift beyond height-based restrictions, urging designers and policy makers to focus on design decisions to conserve resources, lower emissions, and support circular-economy objectives