Global sensitivity analysis of England's housing energy model

Abstract

Housing energy models support informed decision-making for energy efficiency and CO2 reduction strategies. However, they are subject to multiple sources of uncertainty. Previous studies have analysed uncertainties using a local one-at-a-time approach, but this suffers from significant limitations. Here two global sensitivity analysis techniques, elementary effects and a variance-based method, have been employed to overcome these limitations. Correct understanding of model sensitivities matters, for interpreting findings and directing research to reduce uncertainties. Analysis of the Cambridge Housing Model, a Standard Assessment Procedure (SAP)-based housing energy model for England, finds good agreement between the global analyses but there are major differences compared with the local analysis. We identify SAP wall U-values and demand temperature as by far the most significant uncertain parameters; along with SAP roof, window and floor U-values these account for 96% of the observed variation in outputs. This could have major implications for national-level estimates of savings based on such models.