Learning from 'horror' stories: a plan of work to reduce the performance gap in deep retrofit

Over the past 20 years efforts have been made to bridge the performance gap by developing design guidance and reports to raise awareness and increase construction quality of the delivery and handover stages; as well as improving tools and prediction methods by validating them with real data comparing anticipated performance with achieved energy use. The complexity of the gap 'problem' increases in deep, low-carbon refurbishment processes. Both the scale and quality of construction work need to be increased if challenging emission reduction targets are to be met. Established professional work plan frameworks (e.g. RIBA and Soft Landings) have been designed mainly with new build in mind without explicitly capturing important stages of a retrofit project that close the loop from in-use to design and back to in-use. The Appraisal (or Strategic) stage misses important diagnostic actions for evaluating client/occupant past experience and assessing existing building energy performance and Indoor Environmental Quality. Similarly although Project roles are described, they do not include the skills/knowledge that individuals (or teams) need; or the tools/ methods that can be used to manage and reduce unforeseen risks related to the existing building condition. This paper presents a modified version of the RIBA Plan of Work, which shows existing and additional workstages for deep refurbishments in a continuous cycle, linking roles to skills, knowledge and tools. Drawing upon evidence from pioneering empirical studies in deep refurbishment in the UK, the notion of 'failures' and key lessons from previous 'horror' and 'learning' retrofitting stories are used here to highlight problems and risks in each of the proposed work stages; and to address the major changes needed in traditional processes to reduce the retrofit performance gap.