oa Closing the performance gap

This presentation will examine where the building performance gap comes from and how the industry can minimise it through better understanding of design analysis and learning from buildings in operation. Over the years the green agenda within building design has become increasingly important. It’s only until very recently that designers, and other construction colleagues, have had the technology and know-how to validate how our buildings are performing in real terms in comparison to what was expected from the design stage. The results prove interesting with a common thread, often the building isn’t performing as predicted. Invariably the divergence in results show the real building performing far worse than expected. Why is this? The Carbon Trust published a report, ‘Closing the Gap’, in April 2012. One of the key findings is the confusion that compliance models should somehow suffice for design analysis and in some cases mistakenly used as a form of operational energy prediction. The compliance model is simply a benchmark exercise and omits key elements within the building in its calculation. For example, unregulated loads such as plug loads, server rooms, external lighting and so on. This is ultimately why the EPC, currently, won’t align with the DEC, however your design model could, and a growing number within our industry would say should. The Carbon Trust report further concludes that during the design process we should distinguish between these model types and focus on the design model rather than being driven by compliance. In addition the report concludes that we should also develop our understanding of soft landings and post occupancy building monitoring, and increase their application to benefit our design decisions through lessons learnt. However, understanding our analysis at design stage is only one half of this challenge, the other is understanding how buildings are operating and learning from them. It is all well and good believing that a building is sustainable because it appears to do so at the design stage, but how sustainable is it in reality? How do we know if we are not checking? Soft Landings is keys to this, but we need to correlate building performance against the design. We need to quantify the Performance Gap in the same level of detail which we analyse buildings in simulation software. This presentation will consider the ways in which we can make better use of the latest technology to calibrate our building models and create strategies that can be implemented across a building’s life to help make smarter decisions and enable strategic energy/carbon reduction planning which meets both environmental and financial targets.