‘Mind the gap’: The difference, in performance, between design and the building ‘in-use’
Abstract
The non-domestic building stock is inefficient with respect to energy and the reasons given are devoid of substantive evidence to back them up. Buildings rarely perform as well as their designers predicted, and energy consumption and costs are, on average, double what was expected. This difference has become known as the performance gap. To address this problem, operators of commercial and public buildings need clear and realistic guidance on targeting energy running costs and on the potential savings available. To truly understand how a building uses energy, it is necessary to know about the building itself and about how it is used. However, what is missing are ‘real-life’ exemplars to investigate the actual causes of the performance gap and propose practical solutions. Liaising with the industry, a number of possible causes have been proposed: (a) lack of maintenance due to resource and skills shortage; (b) limited data; (c) modelling tools limited to asset data that don’t take into account operational parameters; and (d) lack of practical solutions and their costs. All of these may or may not be valid, and there is a need to join asset with operation data with targeting auditing of both the building and its operation to investigate the causes of poor performance.
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Author's Biography
Andy Lewry DIC, CEng, CSci, FIMMM, CEnv, MSocEnv, FEMA has 19 years’ varied technical, marketing and management experience within the carbon and energy management industry, preceded by a further 10 years’ similar experience within various parts of the environmental and construction sectors. Andy is a chartered engineer and a Fellow of both the Institute of Materials (IOM3) and the Energy Managers’ Association, as well as a Prince 2 qualified project manager. He is currently the principal technical consultant for the BREEAM Existing Buildings Team in BRE Global. Andy has authored and published best practice publications on energy management, energy audits, building control and building energy management systems. Recently he produced guidance on ‘Bridging the performance gap: Understanding predicted and actual energy use of buildings’, Journal of Building Survey, Appraisal & Valuation, Vol. 3, No. 4, and ‘Producing the business case for investment in energy efficiency’, Journal of Building Survey, Appraisal & Valuation, Vol. 4, No. 1. He was also part of the UK Green Building Council’s task group that produced the ‘Delivering Building Performance’ report on 11th May, 2016, which lays out the success factors and steps required to tackle the gap between building design and building performance.
Lorna Hamilton (senior statistician) currently leads on quantitative analysis aspects in BRE’s Social Research Team. She has experience of analysing and modelling a wide variety of data and specialises in the application of generalised linear models for correlated data. She has worked with both large and complex data sets for a variety of government, European Commission and commercially funded projects.
Citation
Lewry, Andy and Hamilton, Lorna (2017, June 1). ‘Mind the gap’: The difference, in performance, between design and the building ‘in-use’. In the Journal of Building Survey, Appraisal & Valuation, Volume 6, Issue 1. https://doi.org/10.69554/CGAJ2474.
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