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.

Keywords:

• household energy
• global sensitivity analysis
• uncertainty analysis
• elementary effects
• variance-based analysis
• Cambridge Housing Model

Acknowledgements

Developing and evaluating the Cambridge Housing Model is part of Cambridge Architectural Research's work for the UK's Department of Energy and Climate Change.

Notes

1. The Cambridge Housing Model can be downloaded from DECC's website: https://www.gov.uk/government/organisations/department-of-energy-climate-change/series/domestic-energy-fact-file-and-housing-surveys