Parametric contribution of building form to whole-life carbon decision-making.

Existing buildings generate 30% of global emissions because of the energy required to heat, cool and power them. Mass improvements in building fabric efficiency and heating/cooling systems are therefore imperative. Fast-running modelling approaches are thus necessary to identify appropriate interventions for the global building stock. This paper presents a new parametric formulation to determine the best whole-life carbon intervention as a function of building form. We demonstrate that buildings of inefficient form have greater potential for energy savings, providing a useful prioritization tool for future planning decisions. We present results as a novel graphical tool, which can be used to identify the lowest carbon scenario for any building form across a combination of building storeys and glazing ratios. This is applied to a cool-temperate climate, comparing a retrofit scenario, to the option of replacement with new construction. Finally, we apply the formulation to a subset of the UK educational building stock, assessing 15 193 forms. For this scenario, we conclude that retrofit always results in lower whole-life carbon compared to replacement with attainable new construction standards. This work provides practical assistance with early stage decision-making and theoretical understanding of how form influences energy consumption and whole- life carbon emissions.