Closing the energy performance gap in zero carbon homes - pro-active identification, prioritisation and mitigation of causes using FMEA.

The energy consumption of new homes in the UK routinely exceeds design predictions, in some cases by more than 100%. Work to date suggests multiple causes for this so-called “performance gap”, ranging from technical/design issues through to procurement and behavioural influences. These varied causes are often difficult to detect and may be viewed as trivial or inevitable by the parties responsible for them. Addressing these issues not only requires concurrent technical and organisational solutions, but also a means of predicting which issues are likely to be significant for a given project. In the manufacturing industry this scenario is often addressed using a methodology called Failure Mode and Effects Analysis (FMEA). Although some building component manufacturers make use of FMEA, there is little documented evidence of this technique being applied at the whole building level. In this paper we argue that FMEA is potentially well suited to addressing the energy performance gap for dwellings, but that the approach must be carefully tailored to achieve this task. The Bicester Ecotown Process Improvement Toolkit (BEPIT) research project provides a unique opportunity to develop and test this technique, by means of an iterative application of FMEA on a development of 393 true zero carbon homes. The first iteration is described in terms of both the methodological development, and the performance effect produced at project level. This learning in turn informs a discussion of the wider potential for the use of FMEA to close the energy performance gap. It is argued that the method and approach might be applicable to other building types where similar performance concerns exist.