Towards the development of new energy performance indicators for the external walls of residential buildings

• Nine new metrics were developed as potential wall energy performance indicators.
• The metrics were assessed for different wall types and a wide range of climates.
• The equivalent U-factor was found to be a superior indicator for housing.

This paper assesses nine types of dynamic and equivalent U-factors for their ability to predict the relative energy performance of different types of external walls, with varying levels of insulation, thermal mass and solar absorptance, when used in housing. A simulation analysis is undertaken to determine the energy performance of different wall designs at eight cities, and to determine the dynamic and equivalent U-factors of those walls. The results show that there is a strong correlation (R2 > 0.7) between wall energy performance and the equivalent U-factor at all but the coldest of the locations. The equivalent U-factor shows promise as a wall energy performance indicator for global housing.