The impact of multi-story building design considerations on embodied carbon emissions, cost, and operational energy has been revealed
Using a computer model, researchers estimate that up to six gigatonnes of carbon could be saved by 2050 if new multi-storey buildings follow certain recommendations during the design process. All these recommendations, which could also save between 28 and 44% of annual heating and cooling costs, use technology that is currently available.
Construction and operation of buildings account for more than one-third of global emissions and energy use. While buildings are a large part of the current problem, they are also a significant lever for change, say researchers from the Universities of Cambridge and Bath, who explored the decisions architects, engineers and urban planners must negotiate. For their study, the researchers looked at shape, size, layout, structural system, windows, insulation, ventilation, and use parameters, for both residential and office buildings, across different climates.
The researchers built a model that allowed them to estimate, for the first time, the relative importance of these early-stage design decisions in a whole building context. Their findings are reported in the journal Applied Energy.
The study found that increasing building compactness, using steel or timber instead of concrete frames, smaller windows with the optimal glazing for a given climate, and using mechanical ventilation with heat recovery, are the best way to decrease embodied emissions and operational energy. The most significant effects on construction costs meanwhile, were the choice of frame material and whether to install mechanical ventilation.
H.L. Gauch, C.F. Dunant, W. Hawkins, A. Cabrera Serrenho. What really matters in multi-storey building design? A simultaneous sensitivity study of embodied carbon, construction cost, and operational energy. Applied Energy, 2023; 333: 120585 DOI: 10.1016/j.apenergy.2022.120585
Buildings account for over one-third of global emissions and energy use. Meeting climate pledges will require achieving high operational energy efficiency with low embodied impacts in new construction. Yet, a systematic identification of the relative influence of building design parameters on both operational and embodied efficiencies has rarely been attempted. In this paper we explore for the first time the sensitivity of a wide range of design and operation parameters in terms of embodied carbon, construction cost, as well as heating and cooling loads for multi-storey buildings. We devised a model to estimate the relative importance of a large set of input variables, describing a building’s shape, size, layout, structure, ventilation, windows, insulation, air, and use for residential and office multi-storey buildings, across different climates. We found that increasing building compactness, using steel or timber instead of concrete frames, lowering window-to-wall ratio, choosing the most suitable glazing, and employing mechanical ventilation with heat recovery are the most important measures to decrease embodied emissions and operational energy. The most significant trade-offs with construction cost were found for the choice of frame material and in the decision whether to install mechanical ventilation. We estimate that 28–44% of yearly heating and cooling energy and 6 Gt cumulative embodied CO2e until 2050 could be saved in multi-storey buildings, without employing new technologies.
